Updated on 2024/02/26

写真a

 
KAMEYAMA Tatsuya
 
Organization
Graduate School of Engineering Materials Chemistry 1 Associate professor
Graduate School
Graduate School of Engineering
Undergraduate School
School of Engineering Chemistry and Biotechnology
Title
Associate professor
Contact information
メールアドレス

Degree 1

  1. 博士(工学) ( 2011.3   名古屋大学 ) 

Research Interests 8

  1. Photoelectrochemistry

  2. Photoluminescent materials

  3. Quantum dots

  4. Photoluminescent materials

  5. Solar cells

  6. Photoelectrochemistry

  7. Nanoparticles

  8. Nanostructure

Research Areas 2

  1. Others / Others  / 光電気化学

  2. Nanotechnology/Materials / Nanomaterials

Research History 6

  1. 名古屋大学大学院   工学研究科 応用物質化学専攻   准教授

    2021.6

  2. JST さきがけ研究員(兼任)

    2018.10 - 2022.3

  3. 名古屋大学大学院   工学研究科 応用物質化学専攻   助教

    2017.4 - 2021.5

  4. Nagoya University   Graduate School of Engineering Department of Crystalline Materials Science Nano-Structured Solid Chemistry   Assistant Professor

    2012.10 - 2017.3

  5. JX日鉱日石金属(現JX金属)株式会社 主任

    2011.4 - 2012.9

  6. 日本学術振興会 特別研究員

    2009.4 - 2011.3

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Education 3

  1. Nagoya University   Graduate School, Division of Engineering

    - 2011.3

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    Country: Japan

  2. Nagoya University   Graduate School, Division of Engineering

    - 2011.3

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    Country: Japan

  3. Nagoya University   Faculty of Engineering

    - 2006.3

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    Country: Japan

Professional Memberships 6

  1. 日本化学会

  2. 電気化学会

  3. 光化学会

  4. 電気化学会

  5. 日本化学会

  6. 光化学会

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Awards 3

  1. 学術賞

    2022.3   公益財団法人永井科学技術財団  

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    Award type:Award from publisher, newspaper, foundation, etc.  Country:Japan

  2. 第11回本多-藤嶋賞

    2015.3   電気化学会 光電気化学懇談会  

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    Award type:Award from international society, conference, symposium, etc.  Country:Japan

  3. 第24回日本MRS年次大会奨励賞

    2015.1   日本MRS学会  

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    Country:Japan

 

Papers 112

  1. Controlling the visible-light driven photocatalytic activity of alloyed ZnSe-AgInSe<sub>2</sub>quantum dots for hydrogen production Reviewed International coauthorship

    Hsieh Ping-Yen, Kameyama Tatsuya, Takiyama Takayuki, Masuoka Ko, Yamamoto Takahisa, Hsu Yung-Jung, Torimoto Tsukasa

    JOURNAL OF MATERIALS CHEMISTRY A   Vol. 8 ( 26 ) page: 13142 - 13149   2020.7

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1039/d0ta04127k

    Web of Science

  2. Rod-shaped Zn-Ag-In-Te nanocrystals with wavelength-tunable band-edge photoluminescence in the near-IR region

    Tatsuya Kameyama, Kouta Sugiura, Yujiro Ishigami, Takahisa Yamamoto, Susumu Kuwabata, Tomoki Okuhata, Naoto Tamai, Tsukasa Torimoto

    Journal of Materials Chemistry C   Vol. 6 ( 8 ) page: 2034 - 2042   2018.2

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Royal Society of Chemistry  

    Rod-shaped nanocrystals (NCs) composed of ZnTe-AgInTe2 solid solution ((AgIn)xZn2(1-x)Te2, ZAITe) were synthesized in a 1-dodecanethiol solution. The resulting ZAITe NCs of 4-5 nm in width and 16-18 nm in length showed exciton peaks in the absorption spectra, regardless of their composition. The energy gap was enlarged from 1.2 to 1.6 eV by decreasing the x value of the NCs from 1.0 to 0.25. A sharp photoluminescence (PL) peak was observed in each PL spectrum of the NCs with x values of 1.0-0.5, assignable to band-edge emission, while NCs with x = 0.25 showed an additional broad PL peak originating from the defect sites due to the increased non-stoichiometry of NCs. With a decrease in x from 1.0 to 0.25, the band-edge PL peak was blue-shifted from 1010 to 809 nm in the near-IR region, accompanied by a decrease in the corresponding PL quantum yield from 47% to 0.07% due to the diminution of radiative recombination rate.

    DOI: 10.1039/c7tc05624a

    Web of Science

    Scopus

  3. Quantum-Dot Light-Emitting Diodes Exhibiting Narrow-Spectrum Green Electroluminescence by Using Ag-In-Ga-S/GaSx Quantum Dots Reviewed

    Motomura, G; Uematsu, T; Kuwabata, S; Kameyama, T; Torimoto, T; Tsuzuki, T

    ACS Applied Materials and Interfaces   Vol. 15 ( 6 ) page: 8336 - 8344   2023.3

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1021/acsami.2c21232

  4. Direct Detection of Long-Range Interdomain Auger Recombination in Dumbbell-Shaped Quasi-Type-II Nanoparticle Reviewed

    Koga, M ; Masuoka, K ; Tsuneizumi, S ; Kameyama, T ; Ito, S ; Torimoto, T ; Miyasaka, H

    Journal of Physical Chemistry Letters   Vol. 13 ( 29 ) page: 6845 - 6851   2022.10

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1021/acs.jpclett.2c01077

  5. Composition control of alloy nanoparticles consisting of bulk-immiscible Au and Rh metals via an ionic liquid/metal sputtering technique for improving their electrocatalytic activity Reviewed

    Akiyoshi, K ; Watanabe, Y ; Kameyama, T ; Kawawaki, T ; Negishi, Y ; Kuwabata, S; Torimoto, T

    Physical Chemistry Chemical Physics   Vol. 24 ( 39 ) page: 24335 - 24344   2022.10

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1039/d2cp01461k

  6. Multifunctional Magnetic CuS/Gd2O3 Nanoparticles for Fluorescence/Magnetic Resonance Bimodal Imaging-Guided Photothermal-Intensified Chemodynamic Synergetic Therapy of Targeted Tumors Reviewed

    Luo, MC ; Yukawa, H ; Sato, K; Tozawa, M; Tokunaga, M; Kameyama, T ; Torimoto, T ; Baba, Y

    ACS Applied Materials and Interfaces   Vol. 14 ( 30 ) page: 34365 - 34376   2022.8

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1021/acsami.2c06503

  7. Development of plasmonic thin-layer chromatography for size-selective and optical-property-dependent separation of quantum dots Invited Reviewed

    Torimoto, T; Yamaguchi, N; Maeda, Y; Akiyoshi, K; Kameyama, T ; Nagai, T; Shoji, T; Yamane, H; Ishihara, H ; Tsuboi, Y

    NPG Asia Materials   Vol. 14 ( 1 ) page: 64   2022.7

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1038/s41427-022-00414-3

  8. Optical trapping of nanoparticles in superfluid helium

    Minowa, Y ; Geng, X ; Keisuke, K ; Sato, K ; Kameyama, T ; Torimoto, T ; Ashida, M

    Optica   Vol. 9 ( 1 ) page: 139 - 144   2022.1

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1364/OPTICA.447557

  9. Red-light-activatable ruthenium phthalocyanine catalysts Reviewed

    Yuta Ishikawa, Tatsuya Kameyama, Tsukasa Torimoto, Hajime Maeda, Masahito Segi, Taniyuki Furuyama

    Chemical Communications   Vol. 57 ( 99 ) page: 13594 - 13597   2021.12

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Royal Society of Chemistry (RSC)  

    Phthalocyanine ruthenium complexes were identified as red-light activatable catalysts for trifluoromethylation reactions.

    DOI: 10.1039/d1cc06307c

    Web of Science

  10. Optical Trapping of Nanocrystals at Oil/Water Interfaces: Implications for Photocatalysis Reviewed

    Yasuyuki Tsuboi, Shota Naka, Daiki Yamanishi, Tatsuya Nagai, Ken-ichi Yuyama, Tatsuya Shoji, Bunsho Ohtani, Mamoru Tamura, Takuya Iida, Tatsuya Kameyama, Tsukasa Torimoto

    ACS Applied Nano Materials   Vol. 4 ( 11 ) page: 11743 - 11752   2021.11

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:American Chemical Society (ACS)  

    DOI: 10.1021/acsanm.1c02335

    Web of Science

  11. Photoluminescence properties of quinary Ag-(In,Ga)-(S,Se) quantum dots with a gradient alloy structure forin vivobioimaging Reviewed

    Nurmanita Rismaningsih, Hiroki Yamauchi, Tatsuya Kameyama, Takahisa Yamamoto, Saho Morita, Hiroshi Yukawa, Taro Uematsu, Yoshinobu Baba, Susumu Kuwabata, Tsukasa Torimoto

    Journal of Materials Chemistry C   Vol. 9 ( 37 ) page: 12791 - 12801   2021.10

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    Language:English   Publishing type:Research paper (scientific journal)  

    Multinary semiconductor quantum dots (QDs) composed of group I-III-VI elements have received much attention for wide-ranging applications due to their low level of toxicity and tunable optical properties. The chemical composition and particle size are important parameters for controlling the physicochemical properties of these QDs. In this study, we prepared quinary QDs of an Ag-(In,Ga)-(S,Se) semiconductor (AIGSSe) by thermolysis of precursors in an organic solution with two-step heat treatment and evaluated their physicochemical properties as a function of Se fraction. The energy gap (Eg) of QDs decreased from 1.9 to 1.5 eV with an increase in the Se/(S + Se) ratio from 0 to 1, accompanied by a shift of the valence band maximum to a higher energy level. The obtained AIGSSe QDs exhibited a sharp band-edge PL peak, the wavelength of which was red-shifted from 580 to 790 nm with a decrease in theirEg. The PL intensity was remarkably enlarged by the surface coating with a GaSxshell, the highest PL quantum yield being 50% for the PL peak at 580 nm. AIGSSe QDs with an Se/(S + Se) ratio of 0.50 exhibited a near-IR PL peak at 790 nm, which is suitable forin vivobioimaging in the wavelength range of the first biological window. By incorporating GaSx-coated AIGSSe QDs (Se/(S + Se) = 0.50) into liposomes, the QDs were transferred into aqueous solutions without significant deterioration of both the PL peak outline and quantum yield, though a broad PL peak originating from defect sites appeared with a relatively large PL intensity when GaSx-coated Ag-(In,Ga)-S QDs that did not contain Se were used.In vivoimaging of a mouse was successfully performed by detecting the band-edge emission at 790 nm of AIGSSe QDs injected subcutaneously in the back of the mouse.

    DOI: 10.1039/d1tc02746h

    Web of Science

    Scopus

  12. Perylene-Cy3 FRET System to Analyze Photoactive DNA Structures Reviewed

    Kawai Hayato, Doi Tetsuya, Ito Yuka, Kameyama Tatsuya, Torimoto Tsukasa, Kashida Hiromu, Asanuma Hiroyuki

    CHEMISTRY-A EUROPEAN JOURNAL   Vol. 27 ( 50 ) page: 12845 - 12850   2021.9

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    Language:English  

    DOI: 10.1002/chem.202101738

    Web of Science

  13. Optical force mapping at the single-nanometre scale Reviewed

    Junsuke Yamanishi, Hidemasa Yamane, Yoshitaka Naitoh, Yan Jun Li, Nobuhiko Yokoshi, Tatsuya Kameyama, Seiya Koyama, Tsukasa Torimoto, Hajime Ishihara, Yasuhiro Sugawara

    Nature Communications   Vol. 12 ( 1 )   2021.6

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Springer Science and Business Media LLC  

    <title>Abstract</title>Three-dimensional (3D) information of the optical response in the nanometre scale is important in the field of nanophotonics science. Using photoinduced force microscopy (PiFM), we can visualize the nano-scale optical field using the optical gradient force between the tip and sample. Here, we demonstrate 3D photoinduced force field visualization around a quantum dot in the single-nanometre spatial resolution with heterodyne frequency modulation technique, using which, the effect of the photothermal expansion of the tip and sample in the ultra-high vacuum condition can be avoided. The obtained 3D mapping shows the spatially localized photoinduced interaction potential and force field vectors in the single nano-scale for composite quantum dots with photocatalytic activity. Furthermore, the spatial resolution of PiFM imaging achieved is ~0.7 nm. The single-nanometer scale photoinduced field visualization is crucial for applications such as photo catalysts, optical functional devices, and optical manipulation.

    DOI: 10.1038/s41467-021-24136-2

    Web of Science

    Other Link: http://www.nature.com/articles/s41467-021-24136-2

  14. Incoherent Optical Tweezers on Black Titanium Reviewed

    Sayaka Hashimoto, Yuki Uenobo, Ryota Takao, Ken-ichi Yuyama, Tatsuya Shoji, Denver P. Linklater, Elena Ivanova, Saulius Juodkazis, Tatsuya Kameyama, Tsukasa Torimoto, Yasuyuki Tsuboi

    ACS Applied Materials & Interfaces   Vol. 13 ( 23 ) page: 27586 - 27593   2021.6

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:American Chemical Society (ACS)  

    DOI: 10.1021/acsami.1c04929

    Web of Science

  15. Green Electroluminescence Generated by Band-edge Transition in Ag-In-Ga-S/GaSx Core/shell Quantum Dots Reviewed

    Motomura Genichi, Iwasaki Yukiko, Kameyama Tatsuya, Torimoto Tsukasa, Uematsu Taro, Kuwabata Susumu, Tsuzuki Toshimitsu

    ITE TRANSACTIONS ON MEDIA TECHNOLOGY AND APPLICATIONS   Vol. 9 ( 4 ) page: 222 - 227   2021

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    Language:English  

    Web of Science

  16. [Paper] Green Electroluminescence Generated by Band-edge Transition in Ag-In-Ga-S/GaS&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; Core/shell Quantum Dots

    Genichi Motomura, Yukiko Iwasaki, Tatsuya Kameyama, Tsukasa Torimoto, Taro Uematsu, Susumu Kuwabata, Toshimitsu Tsuzuki

    ITE Transactions on Media Technology and Applications   Vol. 9 ( 4 ) page: 222 - 227   2021

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    Publishing type:Research paper (scientific journal)   Publisher:Institute of Image Information and Television Engineers  

    DOI: 10.3169/mta.9.222

  17. Synthesis of ring-shaped Ag-Pt nanoparticles for the application to plasmon-enhanced electrocatalysts

    Kameyama Tatsuya, Ota Naoki, Sasamoto Kosuke, Torimoto Tsukasa

    OPTICAL MANIPULATION AND STRUCTURED MATERIALS CONFERENCE 2021   Vol. 11926   2021

  18. Electroluminescence from band-edge-emitting AgInS<sub>2</sub>/GaS<sub>x</sub> core/shell quantum dots Reviewed

    Genichi Motomura, Kei Ogura, Yukiko Iwasaki, Taro Uematsu, Susumu Kuwabata, Tatsuya Kameyama, Tsukasa Torimoto, Toshimitsu Tsuzuki

    Applied Physics Letters   Vol. 117 ( 9 ) page: 091101 - 091101   2020.8

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AIP Publishing  

    DOI: 10.1063/5.0018132

    Web of Science

  19. Controlling the oxidation state of molybdenum oxide nanoparticles prepared by ionic liquid/metal sputtering to enhance plasmon-induced charge separation Reviewed

    Kazutaka Akiyoshi, Tatsuya Kameyama, Takahisa Yamamoto, Susumu Kuwabata, Tetsu Tatsuma, Tsukasa Torimoto

    RSC Advances   Vol. 10 ( 48 ) page: 28516 - 28522   2020.8

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    Nanoparticles composed of molybdenum oxide, MoOx, were successfully prepared by room-temperature ionic liquid (RTIL)/metal sputtering followed by heat treatment. Hydroxyl groups in RTIL molecules retarded the coalescence between MoOx NPs during heat treatment at 473 K in air, while the oxidation state of Mo species in MoOx nanoparticles (NPs) could be modified by changing the heat treatment time. An LSPR peak was observed at 840 nm in the near-IR region for MoOx NPs of 55 nm or larger in size that were annealed in a hydroxyl-functionalized RTIL. Photoexcitation of the LSPR peak of MoOx NPs induced electron transfer from NPs to ITO electrodes.

    DOI: 10.1039/d0ra05165a

    Web of Science

    Scopus

  20. Hot electron transfer in Zn-Ag-In-Te nanocrystal-methyl viologen complexes enhanced with higher-energy photon excitation Reviewed

    Kameyama Tatsuya, Sugiura Kouta, Kuwabata Susumu, Okuhata Tomoki, Tamai Naoto, Torimoto Tsukasa

    RSC ADVANCES   Vol. 10 ( 28 ) page: 16361 - 16365   2020.4

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    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1039/d0ra02842h

    Web of Science

  21. Tailored Photoluminescence Properties of Ag(In,Ga)Se<inf>2</inf> Quantum Dots for Near-Infrared in Vivo Imaging Reviewed

    Tatsuya Kameyama, Hiroki Yamauchi, Takahisa Yamamoto, Toshiki Mizumaki, Hiroshi Yukawa, Masahiro Yamamoto, Shigeru Ikeda, Taro Uematsu, Yoshinobu Baba, Susumu Kuwabata, Tsukasa Torimoto

    ACS Applied Nano Materials   Vol. 3 ( 4 ) page: 3275 - 3287   2020.4

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    © 2020 American Chemical Society. Multinary semiconductor quantum dots (QDs) that have less toxicity and show near-infrared light responsivity have attracted much attention for in vivo bioimaging. In this study, we controlled the optical properties of Ag-In-Se QDs by modulating the nonstoichiometry and the degree of Ga3+ doping. Precise tuning of the Ag/In ratio of Ag-In-Se QDs enabled a sharp band-edge emission to emerge without broad defect-site emission. Ga3+ doping into Ag-In-Se (AIGSe) QDs enlarged their energy gap, resulting in a blue shift of the band-edge PL peak from from 890 to 630 nm. The band-edge PL intensity was remarkably enlarged by surface coating with a thin GaSx shell followed by treatment with trioctylphosphine, the highest PL yield being 38% for the PL peak at 800 nm. Thus-obtained QDs were successfully used as near-IR PL probes for three-dimensional in vivo bioimaging in which the wavelengths of excitation and detection lights could be selected in the first biological window, and then the signals were clearly detected from AIGSe@GaSx core-shell QDs injected into biological tissues by ca. 5 mm in depth.

    DOI: 10.1021/acsanm.9b02608

    Web of Science

    Scopus

  22. Synthesis of submicron-sized CdS particles using reverse micelles Reviewed

    Yosuke Minowa, Shohei Kuramoto, Tatsuya Kameyama, Tsukasa Torimoto, Masaaki Ashida

    Journal of Nanophotonics   Vol. 14 ( 2 ) page: 1 - 1   2020.4

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:SPIE-Intl Soc Optical Eng  

    DOI: 10.1117/1.JNP.14.026013

    Web of Science

  23. Efficient quantum-dot light-emitting diodes using ZnS-AgInS2 solid-solution quantum dots in combination with organic charge-transport materials Reviewed

    Genichi Motomura, Kei Ogura, Tatsuya Kameyama, Tsukasa Torimoto, Taro Uematsu, Susumu Kuwabata, Toshimitsu Tsuzuki

    APPLIED PHYSICS LETTERS   Vol. 116 ( 9 )   2020.3

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER INST PHYSICS  

    Colloidal quantum dots (QDs), which exhibit highly saturated color emission, are expected to be used as emitting materials in wide-color-gamut displays. However, the development of low-toxicity alternatives is necessary because QDs with high color purity and highly efficient emission contain toxic materials such as Cd and Pb. In this study, QD light-emitting diodes (QD-LEDs) with ZnS-AgInS2 solid-solution nanoparticles [(AgIn)(x)Zn2(1-x)S2, ZAIS] as low-toxicity QDs were fabricated and their electroluminescence properties were investigated. The ZAIS QDs exhibited red photoluminescence, with a peak wavelength of ca. 700nm. Because the charge-injection barrier of ZAIS QDs without a wide-bandgap shell is relatively low, the QD-LEDs with red ZAIS QDs in combination with organic charge-transport materials induce electron injection from an organic electron-transport layer. These QD-LEDs exhibit an external quantum efficiency of 2.2%, a turn-on voltage of 2.4V, and red emission with chromaticity coordinates (0.66, 0.33).

    DOI: 10.1063/1.5143618

    Web of Science

  24. Temperature dependences of photoluminescence intensities observed from AgInGaS and AgInGaS/GaSx core–shell nanoparticles Reviewed

    Masayoshi Ichimiya, Tatsuya Kameyama, Tsukasa Torimoto, Taro Uematsu, Susumu Kuwabata, Masaaki Ashida

    Journal of Nanophotonics   Vol. 14 ( 1 ) page: 1 - 1   2020.1

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:SPIE-Intl Soc Optical Eng  

    DOI: 10.1117/1.JNP.14.016010

    Web of Science

  25. Enhancement of electrocatalytic oxygen reduction reaction on Au-Ag nanorings by plasmon excitation Reviewed

    Kameyama Tatsuya, Sasamoto Kosuke, Torimoto Tsukasa

    OPTICAL MANIPULATION AND STRUCTURED MATERIALS CONFERENCE 2020   Vol. 11522   2020

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    Authorship:Lead author   Language:English  

    DOI: 10.1117/12.2573520

    Web of Science

  26. Nanotraffic Lights: Rayleigh Scattering Microspectroscopy of Optically Trapped Octahedral Gold Nanoparticles Reviewed

    Shoji Tatsuya, Tamura Mamoru, Kameyama Tatsuya, Iida Takuya, Tsuboi Yasuyuki, Torimoto Tsukasa

    JOURNAL OF PHYSICAL CHEMISTRY C   Vol. 123 ( 37 ) page: 23096 - 23102   2019.9

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1021/acs.jpcc.9b05077

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  27. Non-destructive dispersion of quantum dots into buffer gases toward their optical manipulation

    Mitsutaka Kumakura, Yuta Baba, Takayuki Shimomura, Takayuki Takiyama, Tatsuya Kameyama, Tsukasa Torimoto, Takeshi Moriyasu

    Proceedings of SPIE   Vol. 11141   page: 1114101-161 - 1114101-163   2019.9

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  28. Enhanced Photoelectrochemical Properties of Zn−Ag−In−Te Nanocrystals with High Energy Photon Excitation Reviewed

    Tatsuya Kameyama, Kouta Sugiura, Susumu Kuwabata, Tomoki Okuhata, Naoto Tamai, Tsukasa Torimoto

    ChemNanoMat   Vol. 5 ( 8 ) page: 1028 - 1035   2019.8

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    Language:English   Publishing type:Research paper (scientific journal)  

    © 2019 Wiley-VCH Verlag GmbH &amp; Co. KGaA, Weinheim Multinary nanocrystals (NCs) of I-III-VI-based semiconductors with less toxicity have attracted much attention for the fabrication of efficient light-energy conversion systems. Here we report unique photoelectrochemical properties of ZnTe−AgInTe2 solid solution (ZAITe) NCs with a controllable energy gap in near-IR region. The photoelectrochemical behavior of ZAITe NCs immobilized on an ITO electrode with a thickness of less than one monoparticle layer, resembling a p-type semiconductor photoresponse, was remarkably different from that of ZAITe NC multilayer films: The onset of a cathodic photocurrent was shifted more positively than that of the valence band maximum of ZAITe NCs and the photocurrent generation efficiency was significantly increased, when photons with energy higher than ca. 2.5 eV were irradiated. These phenomena can be explained well by the direct hot hole transfer from ZAITe NCs to the ITO electrode.

    DOI: 10.1002/cnma.201900241

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    Scopus

  29. Nanotraffic Lights: Rayleigh Scattering Microspectroscopy of Optically Trapped Octahedral Gold Nanoparticles Reviewed

    Tatsuya Shoji, Mamoru Tamura, Tatsuya Kameyama, Takuya Iida, Yasuyuki Tsuboi, Tsukasa Torimoto

    The Journal of Physical Chemistry C   Vol. 123 ( 37 ) page: 23096 - 23102   2019.8

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  30. Non-destructive dispersion of quantum dots into gases

    Kumakura M, Koide D, Shimomura T, Baba Y, Takiyama T, Kameyama T, Torimoto T, Moriyasu T

    12TH INTERNATIONAL CONFERENCE ON EXCITONIC AND PHOTONIC PROCESSES IN CONDENSED MATTER AND NANO MATERIALS (EXCON 2018)   Vol. 1220   2019

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1088/1742-6596/1220/1/012039

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  31. Wavelength-Tunable Band-Edge Photoluminescence of Nonstoichiometric Ag-In-S Nanoparticles via Ga3+ Doping Reviewed

    Tatsuya Kameyama, Marino Kishi, Chie Miyamae, Dharmendar Kumar Sharma, Shuzo Hirata, Takahisa Yamamoto, Taro Uematsu, Martin Vacha, Susumu Kuwabata, Tsukasa Torimoto

    ACS APPLIED MATERIALS & INTERFACES   Vol. 10 ( 49 ) page: 42844 - 42855   2018.12

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER CHEMICAL SOC  

    The nonstoichiometry of semiconductor I-III-VI semiconductor nanoparticles, especially the ratio of group Ito group III elements, has been utilized to control their physicochemical properties. We report the solution-phase synthesis of non-stoichiometric Ag-In-S and Ag-In-Ga-S nanoparticles and results of the investigation of their photoluminescence (PL) properties in relation to their chemical compositions. While stoichiometric AgInS2 nanoparticles simply exhibited only a broad PL band originating from defect sites in the particles, a narrow band edge PL peak newly appeared with a decrease in the Ag fraction in the nonstoichiometric Ag-In-S nano-particles. The relative PL intensity of this band edge emission with respect to the defect-site emission was optimal at a Ag/(Ag + In) value of ca. 0.4. The peak wavelength of the band edge emission was tunable from 610 to 500 nm by increased doping with Ga3+ into Ag-In-S nanoparticles due to an increase of the energy gap. Furthermore, surface coating of Ga3+-doped Ag-In-S nanoparticles, that is, Ag-In-Ga-S nanoparticles, with a GaSx shell drastically and selectively suppressed the broad defect-site PL peak and, at the same time, led to an increase in the PL quantum yield (QY) of the band edge emission peak. The optimal PL QY was 28% for Ag-In-Ga-S@GaSx core-shell particles, with green band-edge emission at 530 nm and a full width at half-maximum of 181 meV (41 nm). The observed wavelength tunability of the band-edge PL peak will facilitate possible use of these toxic-element-free I-III-VI-based nanoparticles in a wide area of applications.

    DOI: 10.1021/acsami.8b15222

    Web of Science

  32. Photoluminescence characterization of ZnS-AgInS2 (ZAIS) nanoparticles adsorbed on plasmonic chip studied with fluorescence microscopy Reviewed

    Wataru Minoshima, Ryuya Ito, Takayuki Takiyama, Tatsuya Kameyama, Tsukasa Torimoto, Keiko Tawa

    JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY   Vol. 367   page: 347 - 354   2018.12

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE SA  

    Quantum dots (QDs) are semiconductor nanoparticles showing many advantages for photoluminescence (PL) applications. Since common QDs contain toxic elements such as Cd, Pb, Se, and Te, ZnS-AgInS2 (ZAIS) has been developed a a quantum nanomaterial with low cytotoxicity. In this study, ZAIS@ZnS core-shell QDs coated with carboxyl groups (ZAIS@ZnS-MPA) were prepared as water-soluble nanoparticles. The PL characteristics of ZAIS@ZnS-MPA were studied on a plasmonic chip, which is a substrate with wavelength-scale periodic structures coated with thin metal films, and the PL enhancement of ZAIS by an electromagnetic field derived from grating-coupled surface plasmon resonance (GC-SPR) was also evaluated. The PL spectroscopic characteristics obtained on the grating patterns with a 480 nm-pitch were enhanced in a wider wavelength range. Furthermore, photobleaching, which occurs in conventional fluorescence molecules, was not observed under halogen lamp illumination. The PL and spectroscopic imaging under a microscope indicated the PL characteristics of the ZAIS@ZnS-MPA nanoparticles on the plasmonic chip under appropriate conditions.

    DOI: 10.1016/j.jphotochem.2018.08.032

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  33. Two-photon Absorption Spectrum of Solid Solution Nanocrystals of ZnS-AgInS<inf>2</inf>

    Yasutaka Suzuki, Shozo Onishi, Kazuya Matsumoto, Takayuki Takiyama, Tatsuya Kameyama, Tsukasa Torimoto, Jun Kawamata

    Chemistry Letters   Vol. 47 ( 12 ) page: 1475 - 1477   2018.12

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    © 2018 The Chemical Society of Japan Two-photon absorption behavior of dispersion of solid solution nanocrystals of ZnS-AgInS2 was investigated, the measured maximum two-photon absorption cross-section of this nanoparticle being 3900 GM (1 GM = 10150 cm4 s photon11 mol(particle)11) at 850 nm. The two-photon excited red photoluminescence was observed even by using a femtosecond fiber laser oscillating at 1030 nm.

    DOI: 10.1246/cl.180718

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  34. Narrow band-edge photoluminescence from AgInS<inf>2</inf> semiconductor nanoparticles by the formation of amorphous III–VI semiconductor shells

    Taro Uematsu, Kazutaka Wajima, Dharmendar Kumar Sharma, Shuzo Hirata, Takahisa Yamamoto, Tatsuya Kameyama, Martin Vacha, Tsukasa Torimoto, Susumu Kuwabata

    NPG Asia Materials   Vol. 10   page: 713 - 726   2018.8

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    © 2018, The Author(s). Nanoparticles of I–III–VI semiconductors are promising candidates for novel non-toxic fluorescent materials. However, removal of defect levels responsible for their broad-band emission has not been successful to date. The present study demonstrates, for the first time, the coating of core AgInS2 nanoparticles—one of the I–III–VI group semiconductors with a bandgap in the visible region—with III–VI group semiconductors. The AgInS2/InSx and AgInS2/GaSx (x = 0.8–1.5) core/shell structures generate intense narrow-band photoluminescence originating from a band-edge transition at a wavelength shorter than that of the original defect emission. Microscopic analyses reveal that the GaSx shell has an amorphous nature, which is unexpected for typical shell materials such as crystalline lattice-matching ZnS. Single-particle spectroscopy shows that the average linewidth of the band-edge photoluminescence is as small as 80.0 meV (or 24 nm), which is comparable with that of industry-standard II–VI semiconductor quantum dots. In terms of photoluminescence quantum yield, a value of 56% with nearly single-band emission has been achieved as a result of several modifications to the reaction conditions and post-treatment to the core/shell nanoparticles. This work indicates the increasing potential of AgInS2 nanoparticles for use as practical cadmium-free quantum dots.

    DOI: 10.1038/s41427-018-0067-9

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  35. Enhanced Photocatalytic Activity of Zn-Ag-In-S Semiconductor Nanocrystals with a Dumbbell-Shaped Heterostructure Reviewed

    Tatsuya Kameyama, Seiya Koyama, Takahisa Yamamoto, Susumu Kuwabata, Tsukasa Torimoto

    JOURNAL OF PHYSICAL CHEMISTRY C   Vol. 122 ( 25 ) page: 13705 - 13715   2018.6

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    Nanocrystals with a heterojunction of type-II band alignment have attracted much interest for the construction of solar energy conversion systems because photogenerated electrons and holes can be effectively separated at the heterojunction. Here, we report the preparation of heterostructured multinary nanocrystals composed of ZnS-AgInS2 solid solution (ZAIS), which have tunability of the electronic energy structure depending on their chemical composition. Ellipsoidal ZAIS nanocrystal domains with various compositions were epitaxially grown on both termini of preformed ZAIS nanorods as seeds. The resulting nanocrystals had a dumbbell shape composed of two ellipsoidal nanocrystals (ca. 4-6 nm in width x 7-11 nm in length) connected by a nanorod (ca. 4 nm in width x 16-23 nm in length). Because the Zn fraction in the chemical composition was larger in the rod part than in the two tip parts in the nanodumbbell, heterojunctions of type-II or quasi-type-II were formed at the interface between the rod and tip parts, as confirmed by photoluminescence lifetime measurements. Analysis of the energy structure of ZAIS nanodumbbells indicated that photogenerated electrons and holes were effectively and spatially separated at the heterojunction, resulting in localization of the photogenerated electrons in ellipsoidal ZAIS tips in the nanodumbbell but delocalization of holes over the whole nanocrystal. The photocatalytic H-2 evolution rate of ZAIS nanodumbbells was remarkably improved in comparison to those of single-component counterparts, ZAIS nanorods or free ellipsoidal ZAIS nanocrystals with similar sizes, by tuning the chemical composition of the tip parts to optimize the energy structure of thetype-II heterojunction for H-2 evolution.

    DOI: 10.1021/acs.jpcc.8b00255

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  36. Advances in Colloidal I-III-VI2-Based Semiconductor Quantum Dots toward Tailorable Photofunctional Materials Reviewed

    Tatsuya Kameyama

    ELECTROCHEMISTRY   Vol. 86 ( 6 ) page: 291 - 297   2018

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    Group I-III-VI2 semiconductor-based quantum dots, such as AgInS2, CuInS2 and their solid solution with ZnS, have recently been reported to show intense photoluminescence, the wavelength of which is tunable in a wide range from visible to near-infrared (NIR) light regions by controlling their chemical composition and/or size. Due to their low toxicity and tunable optical properties, these multinary semiconductor quantum dots (QDs) have been intensively developed as alternative materials to conventional Cd-and Pb-based QDs for applications to photoluminescent devices, photocatalysts, quantum dot solar cells, and biological imaging materials. In this review, the recent progress in the photofunctionality of I-III-VI2-based semiconductor QDs prepared by the colloidal method is outlined with foucus on two advances: (1) extension of the photoluminescence wavelength to NIR light for in vivo biological imaging and (2) improvement of photoenergy conversion properties by nanostructure control of QDs. (c) The Electrochemical Society of Japan, All rights reserved.

    DOI: 10.5796/electrochemistry.18-6-E2670

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  37. Optical Trapping of Gold and Semiconductor Nanoparticles at Oil-Water Interfaces with a focused near-infrared laser beam Reviewed

    Tatsuya Shoji, Shota Naka, Seiya Koyama, Tatsuya Kameyama, Tsukasa Torimoto, Yasuyuki Tsuboi

    OPTICAL MANIPULATION CONFERENCE   Vol. 10712   2018

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    A tightly focused laser beam exerts optical force on nanoparticles dispersed in an aqueous solution, leading to an optical trapping of them at the focal point. Recently, we have developed plasmonic optical tweezers for soft nano-matters such as DNA, thermoresponsive polymer chains, and dye aggregates. We observed the interested trapping behaviors of the soft nanomaterials on such liquid-solid interfaces. Our attention is paid to such optical trapping of them on interfaces because optical force strongly depends on the dielectric constant of the surrounding medium. In the present study, we demonstrated that optical trapping of quantum dots and octahedral gold nanocrystals at water-oil interface. Dark-field microscopy was a powerful tool to observe the trapping behaviors of the gold nanoparticles, while fluorescence microscopy was used for the observations of the quantum dots.

    DOI: 10.1117/12.2319571

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  38. Preparation of low-toxic Zn-Ag-In-Te quantum dots with tunable near-IR emission toward optical applications Reviewed

    Tatsuya Kameyama, Kouta Sugiura, Yujiro Ishigami, Takahisa Yamamoto, Susumu Kuwabata, Tomoki Okuhata, Naoto Tamai, Tsukasa Torimoto

    OPTICAL MANIPULATION CONFERENCE   Vol. 10712   2018

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    Semiconductor quantum dots (QDs) composed of ZnTe-AgInTe2 solid solution ((AgIn)(x)Zn2(1-x)Te2, ZAITe) were synthesized by a thermal reaction of corresponding metal acetates and a Te precursor in 1-dodecanethiol. TEM observations revealed that rod-shaped QDs with width of ca. 4 nm and length of ca. 16 nm were formed regardless of chemical composition of particles, x value. The absorption onset and the band-edge PL peak energy were enlarged from 1.13 to 1.53 eV and from 1.23 eV to 1.53 eV, respectively, with a decrease in x from 1.0 to 0.25. The observed optical properties of ZAITe QDs were largely tunable in the near-IR region, being suitable for optical applications.

    DOI: 10.1117/12.2317057

    Web of Science

  39. Electrocatalytic Activity of Bimetallic Pd-Au Particle Films Prepared by Sequential Sputter Deposition of Pd and Au onto Hydroxyl-functionalized Ionic Liquid

    Takashi Hamada, Daisuke Sugioka, Tatsuya Kameyama, Susumu Kuwabata, Tsukasa Torimoto

    CHEMISTRY LETTERS   Vol. 46 ( 7 ) page: 956 - 959   2017.7

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    Bimetallic Pd-Au nanoparticle films were sputter-deposited on the surface of hydroxyl-functionalized ionic liquid by sequential metal sputtering of Pd and Au. The resulting films having a partially alloyed surface exhibited high electrocatalytic activity for ethanol oxidation, the degree being dependent on both the order of metal sputtering and the chemical composition of resulting bimetallic particles. The optimum catalytic activity was obtained for the bimetallic film with a Au fraction of 41% prepared by sequential sputtering of Pd followed by Au.

    DOI: 10.1246/cl.170242

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  40. Influence of Zn on the photoluminescence of colloidal (AgIn)(x)Zn2(1-x) S-2 nanocrystals

    Sharma Dharmendar Kumar, Hirata Shuzo, Bujak Lukasz, Biju Vasudevanpillai, Kameyama Tatsuya, Kishi Marino, Torimoto Tsukasa, Vacha Martin

    PHYSICAL CHEMISTRY CHEMICAL PHYSICS   Vol. 19 ( 5 ) page: 3963-3969   2017.2

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    DOI: 10.1039/c6cp07550a

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  41. Labeling and in vivo visualization of transplanted adipose tissue-derived stem cells with safe cadmium-free aqueous ZnS coating of ZnS-AgInS2 nanoparticles Reviewed

    Yusuke Ogihara, Hiroshi Yukawa, Tatsuya Kameyama, Hiroyasu Nishi, Daisuke Onoshima, Tetsuya Ishikawa, Tsukasa Torimoto, Yoshinobu Baba

    SCIENTIFIC REPORTS   Vol. 7   page: 40047   2017.1

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    The facile synthesis of ZnS-AgInS2 (ZAIS) as cadmium-free QDs and their application, mainly in solar cells, has been reported by our groups. In the present study, we investigated the safety and the usefulness for labeling and in vivo imaging of a newly synthesized aqueous ZnS-coated ZAIS (ZnS-ZAIS) carboxylated nanoparticles (ZZC) to stem cells. ZZC shows the strong fluorescence in aqueous solutions such as PBS and cell culture medium, and a complex of ZZC and octa-arginine (R8) peptides (R8-ZZC) can achieve the highly efficient labeling of adipose tissue-derived stem cells (ASCs). The cytotoxicity of R8-ZZC to ASCs was found to be extremely low in comparison to that of CdSe-based QDs, and R8-ZZC was confirmed to have no influence on the proliferation rate or the differentiation ability of ASCs. Moreover, R8-ZZC was not found to induce the production of major inflammatory cytokines(TNF-alpha, IFN-gamma, IL-12p70, IL-6 and MCP-1) in ASCs. Transplanted R8-ZZC-labeled ASCs could be quantitatively detected in the lungs and liver mainly using an in vivo imaging system. In addition, high-speed multiphoton confocal laser microscopy revealed the presence of aggregates of transplanted ASCs at many sites in the lungs, whereas individual ASCs were found to have accumulated in the liver.

    DOI: 10.1038/srep40047

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  42. Enhancement of Electrocatalytic Activity of Octahedral Au@ Pt Core-Shell Nanoparticles by the Surface Plasmon Excitation

    Tatsuya Kameyama, Kentaro Sato, Tsukasa Torimoto

    OPTICAL MANIPULATION CONFERENCE   Vol. 10252   2017

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    DOI: 10.1117/12.2274899

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  43. Controlling the Size and Chemical Composition of Multinary Semiconductor Nanocrystals for Improving Photochemical Functions

    KAMEYAMA Tatsuya, KUWABATA Susumu, TORIMOTO Tsukasa

    Hyomen Kagaku   Vol. 38 ( 1 ) page: 18 - 23   2017

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    <p>Multinary I-III-VI<sub>2</sub> group semiconductor nanocrystals, such as CuInS<sub>2</sub>, Cu(InGa)Se<sub>2</sub>, AgInS<sub>2</sub> and their solid solutions with ZnS, have been attracting increasing attention due to their low toxicity, wide range of absorption from UV to visible or near-infrared regions, and tunable energy gap. In this review, we introduce recent progress of solution-phase syntheses of high-quality multinary nanocrystals, which are candidates for alternative materials of Cd- and Pb-based binary nanocrystals showing high toxicity. Physicochemical properties of multinary nanocrystals are tunable depending on their crystal size and chemical composition. For example, nanocrystals of solid solution between AgInS<sub>2</sub> and ZnS exhibited strong photoluminescence, the color of which was controlled from red to green with an increase in the ZnS fraction. The controllability of their photochemical properties is useful to develop novel photofunctional materials for the applications, such as photocatalyst and biomolecule marker.</p>

    DOI: 10.1380/jsssj.38.18

    CiNii Books

  44. Controlling Shape Anisotropy of ZnS-AgInS2 Solid Solution Nanoparticles for Improving Photocatalytic Activity Reviewed

    Tsukasa Torimoto, Yutaro Kamiya, Tatsuya Kameyama, Hiroyasu Nishi, Taro Uematsu, Susumu Kuwabata, Tamaki Shibayama

    ACS APPLIED MATERIALS & INTERFACES   Vol. 8 ( 40 ) page: 27151 - 27161   2016.10

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    Independently controlling the shape anisotropy and chemical composition of multinary semiconductor particles is important for preparing highly efficient photo catalysts. In this study, we prepared ZnS-AgInS2 solid solution ((AgIn)(x)Zn2(i1-)S2, ZAIS) nanoparticles with well-controlled anisotropic shapes, rod, and rice shapes, by reacting corresponding metal acetates with a mixture of sulfur compounds with different reactivities, elemental sulfur, and 1,3-dibutylthiourea, via a two-step heating-up process. The chemical composition predominantly determined the energy gap of ZAIS particles: the fraction of Zn2+ in rod-shaped particles was tuned by the ratio of metal precursors used in the nanocrystal formation, while postpreparative Zn2+ doping was necessary to increase the Zn2+ fraction in the rice-shaped particles. The photocatalytic H-2 evolution rate with irradiation to ZAIS particles dispersed in an aqueous solution was significantly dependent on the chemical composition in the case of using photocatalyst particles with a constant morphology. In contrast, photocatalytic activity at the optimum ZAIS composition, x of 0.35-0.45, increased with particle morphology in the order of rice (size: ca. 9 X ca. 16 nm) < sphere (diameter: ca. 5.5 run) < rod (size: 4.6 X 27 nm). The highest apparent quantum yield for photocatalytic H-2 evolution was 5.9% for rod-shaped ZAIS particles, being about two times larger than that obtained with spherical particles.

    DOI: 10.1021/acsami.6b10408

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  45. Top-Down Synthesis Methods for Nanoscale Catalysts

    Tsukasa Torimoto, Tatsuya Kameyama, Susumu Kuwabata

    Nanocatalysis in Ionic Liquids     page: 171 - 205   2016.8

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    Language:English   Publishing type:Part of collection (book)   Publisher:wiley  

    DOI: 10.1002/9783527693283.ch9

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  46. Temperature-independent formation of Au nanoparticles in ionic liquids by arc plasma deposition Reviewed

    Yoshikiyo Hatakeyama, Satoshi Kimura, Tatsuya Kameyama, Yoshiaki Agawa, Hiroyuki Tanaka, Ken Judai, Tsukasa Torimoto, Keiko Nishikawa

    CHEMICAL PHYSICS LETTERS   Vol. 658   page: 188 - 191   2016.8

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    An effective preparation method of Au nanoparticles (NPs) is presented, wherein an arc plasma deposition technique is combined with ionic liquids (ILs) used as capture media. This method requires no chemical reaction. By selecting ILs, size-controlled Au NPs are produced easily and on a massive scale. (C) 2016 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.cplett.2016.06.044

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  47. Intra- and inter-atomic optical transitions of Fe, Co, and Ni ferrocyanides studied using first-principles many-electron calculations Reviewed

    Shinta Watanabe, Yuki Sawada, Masato Nakaya, Masahito Yoshino, Takanori Nagasaki, Tatsuya Kameyama, Tsukasa Torimoto, Yusuke Inaba, Hideharu Takahashi, Kenji Takeshita, Jun Onoe

    JOURNAL OF APPLIED PHYSICS   Vol. 119 ( 23 )   2016.6

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    We have investigated the electronic structures and optical properties of Fe, Co, and Ni ferrocyanide nanoparticles using first-principles relativistic many-electron calculations. The overall features of the theoretical absorption spectra for Fe, Ni, and Co ferrocyanides calculated using a first-principles many-electron method well reproduced the experimental one. The origins of the experimental absorption spectra were clarified by performing a configuration analysis based on the many-electron wave functions. For Fe ferrocyanide, the experimental absorption peaks originated from not only the charge-transfer transitions from Fe2+ to Fe3+ but also the 3d-3d intra-transitions of Fe3+ ions. In addition, the spin crossover transition of Fe3+ predicted by the many-electron calculations was about 0.24 eV. For Co ferrocyanide, the experimental absorption peaks were mainly attributed to the 3d-3d intra-transitions of Fe2+ ions. In contrast to the Fe and Co ferrocyanides, Ni ferrocyanide showed that the absorption peaks originated from the 3d-3d intra-transitions of Ni3+ ions in a low-energy region, while from both the 3d-3d intra-transitions of Fe2+ ions and the charge-transfer transitions from Fe2+ to Ni3+ in a high-energy region. These results were quite different from those of density-functional theory (DFT) calculations. The discrepancy between the results of DFT calculations and those of many-electron calculations suggested that the intra-and inter-atomic transitions of transition metal ions are significantly affected by the many-body effects of strongly correlated 3d electrons. Published by AIP Publishing.

    DOI: 10.1063/1.4954070

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  48. Formation of a Pt-Decorated Au Nanoparticle Monolayer Floating on an Ionic Liquid by the Ionic Liquid/Metal Sputtering Method and Tunable Electrocatalytic Activities of the Resulting Monolayer

    Daisuke Sugioka, Tatsuya Kameyama, Susumu Kuwabata, Takahisa Yamamoto, Tsukasa Torimoto

    ACS APPLIED MATERIALS & INTERFACES   Vol. 8 ( 17 ) page: 10874 - 10883   2016.5

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    A novel strategy to prepare a bimetallic Au-Pt particle film was developed through sequential sputter deposition of Au and Pt on a room temperature ionic liquid (RTIL). Au sputter deposition onto an RTIL containing hydroxyl-functionalized cations produced a monolayer of Au particles 4.2 nm in size on the liquid surface. Subsequent Pt sputtering onto the original Au particle monolayer floating on the RTIL enabled decoration of individual Au particles with Pt metals, resulting in the formation of a bimetallic Au-Pt particle monolayer with a Pt-enriched particle surface. The particle size slightly increased to 4.8 nm with Pt deposition for 120 min. The shell layer of a bimetallic particle was composed of Au-Pt alloy, the composition of which was tunable by controlling the Pt sputter deposition time. The electrochemical surface area (ECSA) was determined by cyclic voltammetry of bimetallic Au-Pt particle monolayers transferred onto HOPG electrodes by a horizontal liftoff method. The Pt surface coverage, determined by ECSAs of Au and Pt, increased from 0 to 56 mol % with elapse of the Pt sputter deposition time up to 120 min. Thus-obtained Au-Pt particle films exhibited electrocatalytic activity for methanol oxidation reaction (MOR) superior to the activities of pure Au or Pt particles. Volcano-type dependence was observed between the MOR activity and Pt surface coverage on the particles. Maximum activity was obtained for Au-Pt particles with a Pt coverage of 49 mol %, being ca. 120 times higher than that of pure Pt particles. This method enables direct decoration of metal particles with different noble metal atoms, providing a novel strategy to develop highly efficient multinary particle catalysts.

    DOI: 10.1021/acsami.6b01978

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  49. 多元系半導体量子ドットの液相合成と光化学特性制御 Invited Reviewed

    鳥本司, 亀山達矢、桑畑進

    光化学   Vol. 47   page: 9-18   2016

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  50. Single-Step Preparation of Indium Tin Oxide Nanocrystals Dispersed in Ionic Liquids via Oxidation of Molten In-Sn Alloys Reviewed

    D. Sugioka, T. Kameyama, T. Yamamoto, S. Kuwabata, T. Torimoto

    Chem. Commun.   Vol. 52   page: 12241-12244   2016

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  51. Intra-and Inter-Atomic Optical Transitions of Fe, Co, and Ni Ferrocyanides Studied Using First-principles Many-electron calculations Reviewed

    S. Watanabe, Y. Sawada, M. Nakaya, M. Yoshino, T. Nagasaki, T. Kameyama, T. Torimoto, Y. Inaba, H. Takahashi, K. Takeshita, J. Onoe

    J. Appl. Phys.   Vol. 119   page: 235102   2016

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  52. Temperature-Independent Formation of Au Nanoparticles in Ionic Liquids by Arc Plasma Deposition Reviewed

    Y. Hatakeyama, S. Kimura, T. Kameyama, Y. Agawa, H. Tanaka, K. Judai, T. Torimoto, K. Nishikawa,

    Chem. Phys. Lett.   Vol. 658   page: 188-191   2016

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  53. Formation of a Pt-decorated Au Nanoparticle Monolayer Floating on Ionic Liquid by the Ionic Liquid/Metal Sputtering Method and Tunable Electrocatalytic Activities of the Resulting Monolayer Reviewed

    D. Sugioka, T. Kameyama, S. Kuwabata, T. Yamamoto, T. Torimoto

    ACS Appl. Mater. Inter.   Vol. 8   page: 10874-10883   2016

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  54. Crystal Phase-Controlled Synthesis of Rod-Shaped AgInTe2 Nanocrystals for in vivo Imaging in the Near-Infrared Wavelength Region Reviewed

    T. Kameyama, Y. Ishigami, H. Yukawa, S. Taisuke, Y. Baba, T. Ishikawa, S. Kuwabata, T. Torimoto

    Nanoscale   Vol. 8   page: 5435-5440   2016

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  55. Single-Particle Spectroscopy of I-III-VI Semiconductor Nanocrystals: Spectral Diffusion and Suppression of Blinking by Two-color Excitation Reviewed

    D. K. Sharma, S. Hirata, L. Bujak, V. Biju, T. Kameyama, M. Kishi, T. Torimoto, M. Vacha

    Nanoscale   Vol. 28   page: 13687-13694   2016

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  56. Controlling Shape Anisotropy of ZnS-AgInS2 Solid Solution Nanoparticles for Improving Photocatalytic Activity Reviewed

    T. Torimoto, Y. Kamiya, T. Kameyama, H. Nishi, T. Uematsu, S. Kuwabata, T. Shibayama

      Vol. 8   page: 27151-27161   2016

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  57. Crystal phase-controlled synthesis of rod-shaped AglnTe(2) nanocrystals for in vivo imaging in the near-infrared wavelength region

    Tatsuya Kameyama, Yujiro Ishigami, Hiroshi Yukawa, Taisuke Shimada, Yoshinobu Baba, Tetsuya Ishikawa, Susumu Kuwabata, Tsukasa Torimoto

    NANOSCALE   Vol. 8 ( 10 ) page: 5435 - 5440   2016

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    Rod-shaped AgInTe2 nanocrystals (NCs) exhibiting intense nearband edge photoluminescence in the near-infrared (NIR) wavelength region, were successfully prepared by the thermal reaction of metal acetates and Te precursors in 1-dodecanethiol. Increasing the reaction temperature resulted in the formation of larger AgInTe2 NCs with crystal structures varying from hexagonal to tetragonal at reaction temperatures of 280 degrees C or higher. The energy gap was increased from 1.13 to 1.20 eV with a decrease in rod width from 8.3 to 5.6 nm, accompanied by a blue shift in the photoluminescence (PL) peak wavelength from 1097 to 1033 nm. The optimal PL quantum yield was approximately 18% for AgInTe2 NCs with rod widths of 5.6 nm. The applicability of AgInTe2 NCs as a NIR-emitting material for in vivo biological imaging was examined by injecting AgInTe2 NC-incorporated liposomes into the back of a C57BL/6 mouse, followed by in vivo photoluminescence imaging in the NIR region.

    DOI: 10.1039/c5nr07532g

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  58. Single-particle spectroscopy of I-III-VI semiconductor nanocrystals: spectral diffusion and suppression of blinking by two-color excitation Reviewed

    Dharmendar Kumar Sharma, Shuzo Hirata, Lukasz Bujak, Vasudevanpillai Biju, Tatsuya Kameyama, Marino Kishi, Tsukasa Torimoto, Martin Vacha

    NANOSCALE   Vol. 8 ( 28 ) page: 13687 - 13694   2016

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    Ternary I-III-VI semiconductor nanocrystals have been explored as non-toxic alternatives to II-VI semiconductors for optoelectronic and sensing applications, but large photoluminescence spectral width and moderate brightness restrict their practical use. Here, using single-particle photoluminescence spectroscopy on nanocrystals of (AgIn)(x)Zn2(1-x)S2 we show that the photoluminescence band is inhomogeneously broadened and that size distribution is the dominant factor in the broadening. The residual homogeneous linewidth of individual nanocrystals reaches up to 75% of the ensemble spectral width. Single nanocrystals undergo spectral diffusion which also contributes to the inhomogeneous band. Excitation with two lasers with energies above and below the bandgap reveals coexistence of two emitting donor states within one particle. Spectral diffusion in such particles is due to temporal activation and deactivation of one such state. Filling of a trap state with a lower-energy laser enables optical modulation of photoluminescence intermittency (blinking) and leads to an almost two-fold increase in brightness.

    DOI: 10.1039/c6nr03950b

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  59. Solution Phase Syntheses and Photochemical Properties of Multinary Semiconductor Quantum Dots Invited Reviewed

      Vol. 47 ( 1 ) page: 9-18 - 18   2016

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    CiNii Books

  60. Single-step preparation of indium tin oxide nanocrystals dispersed in ionic liquids via oxidation of molten In-Sn alloys

    Daisuke Sugioka, Tatsuya Kameyama, Takahisa Yamamoto, Susumu Kuwabata, Tsukasa Torimoto

    CHEMICAL COMMUNICATIONS   Vol. 52 ( 82 ) page: 12241 - 12244   2016

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    Oxidation of molten In-Sn alloys was carried out in ionic liquids by heat treatment with vigorous stirring, resulting in the formation of indium tin oxide (ITO) nanocrystals. The ITO nanocrystals exhibited a plasmon peak, the peak wavelength of which was blue-shifted with an increase in the Sn fraction in ITO.

    DOI: 10.1039/c6cc06517a

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  61. Facile preparation of core-shell structured AuPt nanoparticle monolayer via ionic liquid/metal sputtering and its electrocatalytic activity

    Sugioka Daisuke, Kameyama Tatsuya, Kuwabata Susumu, Torimoto Tsukasa

    Abstract of annual meeting of the Surface Science of Japan   Vol. 36   page: 105 - 105   2016

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    Language:Japanese   Publisher:The Surface Science Society of Japan  

    DOI: 10.14886/sssj2008.36.0_105

  62. Controlling the Electronic Energy Structure of ZnS-AgInS2 Solid Solution Nanocrystals for Photoluminescence and Photocatalytic Hydrogen Evolution Reviewed

    Tatsuya Kameyama, Takuya Takahashi, Takahiro Machida, Yutaro Kamiya, Takahisa Yamamoto, Susumu Kuwabata, Tsukasa Torimoto

    JOURNAL OF PHYSICAL CHEMISTRY C   Vol. 119 ( 44 ) page: 24740 - 24749   2015.11

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    Simultaneous control of the size and chemical composition is an advantageous strategy to obtain the desired photochemical properties of multinary semiconductor nanocrystals, ZnS-AgInS2 solid solution ((AgIn)(x)Zn2(1-x)S2, ZAIS) nanocrystals (NCs), being different from conventional binary nano crystals. The energy gap (E-g of ZAIS NCs was enlarged with a decrease in particle size due to the quantum size effect or with an increase in ZnS content in the ZAIS solid solution. The levels of the conduction band edge and valence band edge, determined by photoelectron spectroscopy in air, were shifted more negatively and more positively, respectively, with an increase in Eg. A volcano-type dependence was observed between the PL quantum yield (QY) and the size of ZAIS NCs, in which the optimal PL QY for each x value was obtained at a similar particle size around 5-6 nm, except for x = 1.0, and maximum QY was recorded to be 79% for ZAIS NCs prepared with x = 0.5. The photocatalytic activity for H-2 evolution was also greatly dependent on both the size and the chemical composition of ZAIS NCs, and then the highest activity was observed for ZAIS NCs having an average diameter of about 4.2-5.5 nm and E-g of 2.3-2.4 eV. This can be reasonably explained by the enlargement of the driving force to reduce protons in the solution with a negative shift of the conduction band edge of ZAIS NCs and by the quenching of photoexcited ZAIS NCs with an increase in the amount of surface defect sites and/or with the formation of deeper trap sites along with a decrease in the particle size.

    DOI: 10.1021/acs.jpcc.5b07994

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  63. Ultrathin Oxide Shell Coating of Metal Nanoparticles Using Ionic Liquid/Metal Sputtering Reviewed

    Tsukasa Torimoto, Yasuhiro Ohta, Kazuki Enokida, Daisuke Sugioka,Tatsuya Kameyama, Takahisa Yamamoto, Tamaki Shibayama, Kazuki Yoshii, Tetsuya Tsuda, and Susumu Kuwabata

    J. Mater. Chem. A   Vol. 2015 ( 3 ) page: 6177-6186   2015.3

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  64. Ultrathin Oxide Shell Coating of Metal Nanoparticles Using Ionic Liquid/Metal Sputtering Reviewed

    Tsukasa Torimoto, Yasuhiro Ohta, Kazuki Enokida, Daisuke Sugioka, Tatsuya Kameyama, Takahisa Yamamoto, Tamaki Shibayama, Kazuki Yoshii, Tetsuya Tsuda, Susumu Kuwabata

    J. Mater. Chem. A   Vol. 2015 ( 3 ) page: 6177-6186   2015.3

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  65. 高効率で可視光発光する半導体ナノ粒子の液相合成と光機能材料への応用 Invited Reviewed

    鳥本 司, 亀山 達矢, 上松 太郎, 桑畑 進

    色材協会誌   Vol. 87 ( 12 ) page: 430 - 435   2015.3

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    DOI: 10.4011/shikizai.87.430

  66. 高効率で可視光発光する半導体ナノ粒子の液相合成と光機能材料への応用

    鳥本司, 亀山達矢,桑畑 進

    J. Jpn. Soc. Colour Mater.   Vol. 2015 ( 81 ) page: 430-435   2015.2

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  67. 高効率で可視光発光する半導体ナノ粒子の液相合成と光機能材料への応用

    鳥本司, 亀山達矢, 桑畑 進

    J. Jpn. Soc. Colour Mater.   Vol. 2015 ( 81 ) page: 430-435   2015.2

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  68. Well-Controlled Synthesis of Wurtzite-Type Cu2ZnSnS4 Nanoparticles Using Multiple Sulfur Sources via a Two-Step Heating Process

    Hiroyasu Nishi, Takahito Nagano, Tatsuya Kameyama, Susumu Kuwabata,and Tsukasa Torimoto,

    CrystEngCom.   Vol. 2015 ( 17 ) page: 174-182   2015.1

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  69. Single-step preparation of two-dimensionally organized gold particles via ionic liquid/metal sputter deposition

    Daisuke Sugioka, Tatsuya Kameyama, Susumu Kuwabata, Tsukasa Torimoto

    PHYSICAL CHEMISTRY CHEMICAL PHYSICS   Vol. 17 ( 19 ) page: 13150 - 13159   2015

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    Sputtering of noble metals, such as Au, Ag, Pd, and Pt, onto room-temperature ionic liquids (RTILs) enabled the formation of monoparticle films composed of spherical noble metal nanoparticles on the liquid surface only when the RTILs used contained hydroxyl-functionalized cations as a component. Sputter deposition of these metals under the same conditions simply produced well-dispersed metal particles without the formation of any films on the solution surface when pure RTILs with non-functionalized cations were employed. Anionic species, even those containing a hydroxyl group, did not significantly affect the formation of the particle film on the RTIL surface or dispersion of particles in the solution. The size of Au particles could be controlled by varying the sputtering condition regardless of the two-dimensional particle density, which was determined by the composition of RTILs used. An Au monoparticle film on the RTIL surface was easily transferred onto various solid substrates via the horizontal liftoff method without large aggregation even when the substrate surface was highly curved.

    DOI: 10.1039/c5cp01602a

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  70. Well-controlled synthesis of wurtzite-type Cu2ZnSnS4 nanoparticles using multiple sulfur sources via a two-step heating process

    Hiroyasu Nishi, Takahito Nagano, Tatsuya Kameyama, Susumu Kuwabata, Tsukasa Torimoto

    CRYSTENGCOMM   Vol. 17 ( 1 ) page: 174 - 182   2015

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    Wurtzite-type copper zinc tin sulfide (Cu2ZnSnS4) nanoparticles were prepared in dodecanethiol (DDT) solutions by reacting corresponding metal acetates with a mixture of sulfur compounds with different reactivities, elemental sulfur (S) and dibutylthiourea (DBTU), via a two-step heat treatment. Initial heating at 200 degrees C enabled the nucleation of metal sulfide nanoparticles composed of two crystal phases, and subsequent heat treatment at 240 degrees C resulted in the formation of Cu2ZnSnS4 nanoparticles with a wurtzite-type crystal structure. The resulting particles had rod shapes with a stoichiometric composition, the size and shape of which could be controlled by changing both the reaction time and the molar ratio of S and DBTU used in a sulfur precursor. In contrast, spherical Cu2ZnSnS4 nanoparticles with a kesterite-type crystal structure were produced by reaction with pure S as a precursor. The electronic energy levels of the conduction band and valence band edges were determined for wurtzite-type Cu2ZnSnS4 nanoparticles by photoelectrochemical measurement, the individual levels being comparable to those of kesterite-type ones. The light-electricity conversion efficiency varied remarkably depending on the kind of crystal structure: wurtzite-type Cu2ZnSnS4 particles exhibited an efficiency superior to that of the particles with a kesterite-type crystal structure.

    DOI: 10.1039/c4ce01852d

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  71. Ultrathin oxide shell coating of metal nanoparticles using ionic liquid/metal sputtering

    Tsukasa Torimoto, Yasuhiro Ohta, Kazuki Enokida, Daisuke Sugioka, Tatsuya Kameyama, Takahisa Yamamoto, Tamaki Shibayama, Kazuki Yoshii, Tetsuya Tsuda, Susumu Kuwabata

    JOURNAL OF MATERIALS CHEMISTRY A   Vol. 3 ( 11 ) page: 6177 - 6186   2015

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    The surface coating of metal nanoparticles resulting into core-shell structures is expected to improve the physicochemical properties of the nanoparticle cores without changing their size and shape. Here, we developed a novel strategy to coat Au, AuPd or Pt catalyst cores having average sizes smaller than 2.5 nm, which were pre-synthesized in ionic liquids by corresponding metal sputtering, with an extremely thin In2O3 layer (ca. &lt;1.5 nm) by sputter deposition of indium in a room-temperature ionic liquid. The metal cores of Au or AuPd in core-shell particles exhibited superior stability against heat treatments or during electrocatalytic reactions compared to the corresponding bare metal particles. The In2O3 shell coating considerably enhanced the durability of electrocatalytically active Pt particles (1.2 nm). This sequential metal sputter deposition of different metals in ionic liquids will considerably contribute to the exploitation of key nanostructured components for next-generation energy-conversion systems.

    DOI: 10.1039/c4ta06643j

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  72. Widely Controllable Electronic Energy Structure of ZnSe-AgInSe2 Solid Solution Nanocrystals for Quantum-Dot-Sensitized Solar Cells

    Tatsuya Kameyama, Yusuke Douke, Hiroko Shibakawa, Masahide Kawaraya, Hiroshi Segawa, Susumu Kuwabata, Tsukasa Torimoto

    JOURNAL OF PHYSICAL CHEMISTRY C   Vol. 118 ( 51 ) page: 29517 - 29524   2014.12

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    IIIIVI2-semiconductor-based nanocrystals of ZnSeAgInSe2 solid solution ((AgIn)(x)Zn2(1-x)Se2, ZAISe) with average sizes of 3.5-6.2 nm were successfully synthesized through thermal reaction of corresponding metal acetates and selenourea in a hot oleylamine solution. The optical property of ZAISe solid solution nanocrystals was tunable in a broad wavelength region from visible to near-infrared light by changing the composition of solid solution, where the energy gap of ZAISe nanocrystals was enlarged from 1.44 to 3.00 eV with an increase in the fraction of ZnSe in ZAISe, that is, with a decrease in x from 1.0 to 0. Both levels of conduction band and valence band edges, determined by photoelectron spectroscopy in air, were monotonously shifted to higher levels with an increase in the fraction of ZnSe. Quantum-dot-sensitized solar cells were fabricated with porous TiO2 film electrodes immobilized with ZAISe nanocrystals using 3-mercaptopropionic acid as a cross-linking agent. The light conversion efficiency of the thus-obtained cells was enhanced by covering ZAISe nanocrystals with a CdS thin layer by the SILAR method. The photocurrent action spectra agreed well with absorption spectra of ZAISe nanocrystals immobilized on TiO2 electrodes. Maximum energy conversion efficiency of 1.9% was obtained for the cell fabricated with ZAISe nanocrystals with x = 0.5 as a sensitizer under irradiation with simulated solar light of AM 1.5G.

    DOI: 10.1021/jp508769f

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  73. 低毒性元素からなる多元系半導体ナノ粒子の合成とその光化学特性制御

    鳥本司, 亀山達矢,桑畑 進

    セラミックデータブック   Vol. 42   page: 56-60   2014.12

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  74. 低毒性元素からなる多元系半導体ナノ粒子の合成とその光化学特性制御

    鳥本司, 亀山達矢, 桑畑 進

    セラミックデータブック   Vol. 42   page: 56-60   2014.12

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  75. Size-Controlled Synthesis of Ag8SnS6 Nanocrystals for Efficient Photoenergy Conversion Systems Driven by Visible and Near-IR Lights Reviewed

    Tatsuya Kameyama, Shigetoshi Fujita, Hideaki Furusawa, Tsukasa Torimoto

    PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION   Vol. 31 ( 11 ) page: 1122 - 1126   2014.11

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    DOI: 10.1002/ppsc.201400054

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  76. Widely-Controllable Electronic Energy Structure of ZnSe-AgInSe2 Solid Solution Nanocrystals for Quantum Dot-Sensitized Solar Cells Reviewed

    Tatsuya Kameyama, Yusuke Douke, Hiroko Shibakawa, Masahide, Kawaraya, Hiroshi Segawa, Susumu Kuwabata, and Tsukasa Torimoto

    J. Phys. Chem. C   Vol. 2014 ( 118 ) page: 29517-29524   2014.11

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  77. Widely-Controllable Electronic Energy Structure of ZnSe-AgInSe2 Solid Solution Nanocrystals for Quantum Dot-Sensitized Solar Cells Reviewed

    Tatsuya Kameyama, Yusuke Douke, Hiroko Shibakawa, Masahide, Kawaraya, Hiroshi Segawa, Susumu Kuwabata, Tsukasa Torimoto

    J. Phys. Chem. C   Vol. 2014 ( 118 ) page: 29517-29524   2014.11

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  78. Photofunctional Materials Fabricated with Chalcopyrite-Type Semiconductor Nanoparticles Composed of AgInS2 and Its Solid Solutions

    Tsukasa Torimoto, Tatsuya Kameyama, Susumu Kuwabata

    JOURNAL OF PHYSICAL CHEMISTRY LETTERS   Vol. 5 ( 2 ) page: 336 - 347   2014.1

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    Over the past decade, many researchers have made efforts to develop high-quality I-III-VI2 group chalcopyrite-type semiconductor nanoparticles of Cu-based or Ag-based materials, such as CuInS2 Cu(InGa)Se-2, and AgInS2, due to their low toxicity, wide range of absorption from UV to visible or near-infrared regions, and tunable energy gap depending on the chemical composition. Ag-based chalcopyrite-type nanoparticles have attracted much attention because they have physicochemical properties that can be controlled in a manner similar to that for Cu-based nanoparticles but can be synthesized easily under milder reaction conditions than those of Cu-based ones. In this Perspective, we review recent works relating to the preparation of low-toxic nanoparticles of Ag-based chalcopyrite-type semiconductors and their solid solutions, and then we introduce their application as photofunctional materials. Tunability of optical properties has considerably contributed to recent advances in photofunctional applications of chalcopyrite-type semiconductor nanoparticles to sensors, photocatalysts, and solar cells.

    DOI: 10.1021/jz402378x

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  79. 自在に光特性を制御できる半導体ナノ粒子の液相合成と機能材料への応用

    鳥本司, 亀山達矢

    粉体技術   Vol. 6 ( 3 ) page: 281-288   2014

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  80. イオン液体-金属スパッタリング法を用いる合金ナノ粒子の作製と電極触媒への応用

    鳥本司, 亀山達矢, 桑畑進

    触媒   Vol. 56 ( 1 ) page: 34-40   2014

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  81. Preparation of Alloy Nanoparticles via Ionic Liquid-Metal Sputtering Technique and Their Application to Electrocatalysts for Fuel Cells

      Vol. 56 ( 1 ) page: 34-40 - 40   2014

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    CiNii Books

  82. Colloidal Synthesis of Semiconductor Nanoparticles Having Tunable Photochemical Properties and Their Application to Photo-functional Materials

      Vol. 6 ( 3 ) page: 281-288 - 288   2014

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    CiNii Books

  83. ZnS-AgInS2 nanoparticles as a temperature sensor Reviewed

    Yu Matsuda, Tsukasa Torimoto, Tomohiro Kameya, Tatsuya Kameyama, Susumu Kuwabata, Hiroki Yamaguchi, Tomohide Niimi

    SENSORS AND ACTUATORS B-CHEMICAL   Vol. 176   page: 505 - 508   2013.1

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    Luminescent semiconductor nanoparticles have been applied to temperature measurements, because their emission is intense and the emission wavelength can be adjusted by particle size. However, most of luminescent nanoparticles contain highly toxic elements such as Cd, Se, and Te. In this study, the temperature characteristics of a new low-toxic luminescent nanoparticles, ZnS-AgInS2 (ZAIS), have been investigated. The temperature sensitivity of luminescent intensity of ca. -1 %/K was comparable to other luminescent nanoparticles. The thermally induced red shift of ca. 0.1 nm/K was observed, which is similar to other nanoparticles. The measurement revealed that the oxygen sensitivity of ZAIS is negligibly small. It is also shown that ZAIS nanoparticles are photostable compared with CdSe/ZnS. As a result, ZAIS is one of the most preferable candidates to take the place of other toxic nanoparticles especially for bio-related experiments. (C) 2012 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.snb.2012.09.005

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  84. ZnS-AgInS2 Nanoparticles as a Temperature Sensor Reviewed

    Y. Matsuda, T. Torimoto, T. Kameya, T. Kameyama, S. Kuwabata, H. Yamaguchi, T. Niimi

    Sens. Actuators, B   Vol. 176   page: 505   2013

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  85. Tunable Photoelectrochemical Properties of Chalcopyrite AgInS2 Nanoparticles Size-Controlled with a Photoetching Technique

    Tsukasa Torimoto, Masaki Tada, Meilin Dai, Tatsuya Kameyama, Shushi Suzuki, Susumu Kuwabata

    JOURNAL OF PHYSICAL CHEMISTRY C   Vol. 116 ( 41 ) page: 21895 - 21902   2012.10

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    Size-selective photoetching enabled precise size control of chalcopyrite AgInS2 nanoparticles in a basic aqueous solution containing ammonia by selecting the wavelength of monochromatic irradiation light in the range between 650 and 520 nm. The energy gap of the photoetched particles was enlarged from 1.8 to 2.4 eV with a decrease in particle size from 5.1 to 2.7 nm due to the quantum size effect, while the crystal structure and chemical composition of the particles were unchanged after the photoetching processes. AgInS2 nanoparticle-immobilized electrodes exhibited an anodic photocurrent similar to that of n-type semiconductors, the onset potential of which was negatively shifted with a decrease in particle size. Potentials of the conduction band edge (E-CB) and the valence band edge (E-VB) of AgInS2 nanoparticles were estimated from their photoelectrochemical measurements, and they exhibited remarkable size dependence: with a decrease in particle size from 5.1 to 2.7 nm, E-CB was shifted negatively from -0.6 to -1.0 V vs Ag/AgCl, accompanied by a positive shift of E-VB from 1.3 to 1.7 V vs Ag/AgCl.

    DOI: 10.1021/jp307305q

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  86. Solution-phase Synthesis of Stannite-type Ag2ZnSnS4 Nanoparticles for Application to Photoelectrode Materials

    Tetsuya Sasamura, Takaaki Osaki, Tatsuya Kameyama, Tamaki Shibayama, Akihiko Kudo, Susumu Kuwabata, Tsukasa Torimoto

    CHEMISTRY LETTERS   Vol. 41 ( 9 ) page: 1009 - 1011   2012.9

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    Ag2ZnSnS4 (AZTS) nanoparticles were successfully synthesized at relatively low temperature via thermal reaction of corresponding metal acetates and a sulfur source in a hot oleylamine solution, the purity of the particles being dependent on the amount of metal acetates and the reaction temperature. The obtained pure AZTS particles with size of ca. 15 nm exhibited photoresponse with visible light irradiation similar to that of n-type semiconductors.

    DOI: 10.1246/cl.2012.1009

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  87. Tunable photoluminescence from the visible to near-infrared wavelength region of non-stoichiometric AgInS2 nanoparticles Reviewed

    M. Dai, S. Ogawa, T. Kameyama, K. Okazaki, A. Kudo, S. Kuwabata, Y. Tsuboi, T. Torimoto

    J. Mater. Chem.   Vol. 22   page: 12851-12858   2012

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  88. Solution-phase Synthesis of Stannite-type Ag2ZnSnS4 Nanoparticles for Application to Photoelectrode Materials Reviewed

    T. Sasamura, T. Osaki, T. Kameyama, T. Shibayama, A. Kudo, S. Kuwabata, T. Torimoto

    Chem. Lett.   Vol. 41   page: 1009-1011   2012

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  89. Tunable Photoelectrochemical Properties of Chalcopyrite AgInS2 Nanoparticles Size-Controlled with a Photoetching Technique Reviewed

    T. Torimoto, M. Tada, M. Dai, T. Kameyama, S. Suzuki, S. Kuwabata

    J. Phys. Chem. C   Vol. 116   page: 21895-21902   2012

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  90. Tunable photoluminescence from the visible to near-infrared wavelength region of non-stoichiometric AgInS2 nanoparticles

    Meilin Dai, Shoji Ogawa, Tatsuya Kameyama, Ken-ichi Okazaki, Akihiko Kudo, Susumu Kuwabata, Yasuyuki Tsuboi, Tsukasa Torimoto

    JOURNAL OF MATERIALS CHEMISTRY   Vol. 22 ( 25 ) page: 12851 - 12858   2012

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    Non-stoichiometric AgInS2 (AIS) semiconductor particles were synthesized by the thermal decomposition of single-source precursors in solutions of two kinds of primary amines (oleylamine and octylamine). The Ag content in the resulting nanoparticles was controlled by adjusting the chemical composition of the precursor used, in which the mole ratio of Ag+ to total metal ions was varied from 0.1 to 0.7, resulting in the production of non-stoichiometric AIS particles with varying amounts of Ag vacancies. The average size of AIS particles was slightly decreased from 4.3 to 3.8 nm on changing the solvent from oleylamine to octylamine in the preparation, while the particle size seemed to be constant regardless of the content of Ag. On the other hand, the optical properties of AIS particles were considerably modified depending on the Ag content in the particles. The absorption onset was blue-shifted from 750 to 580 nm with a decrease in the Ag content, due to the enlargement of the energy gap of particles. Intense photoluminescence originating from the donor-acceptor pair recombination was observed for each kind of AIS particle and then the photoluminescence peak wavelength was also blue-shifted from 830 to 650 nm, being similar to the behavior of the absorption onset. The maximum photoluminescence quantum yield was ca. 70% for octylamine-modified AIS nanoparticles having a ratio of Ag+ to total metal ions of 0.37, which probably contained the optimum amount of Ag vacancies acting as the sites of donor-acceptor pair recombination with few surface defect sites for non-radiative recombination.

    DOI: 10.1039/c2jm31463k

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  91. Nanoscale Laser Processing of Hollow Silica Microbeads Assisted by Surface Plasmon Resonance of Gold Particles Reviewed

    Koji Furukawa, Tatsuya Kameyama, Ken-ichi Okazaki, Takayuki Yako, Masashi Otsuki, Yasuyuki Tsuboi, Tsukasa Torimoto

    CHEMISTRY LETTERS   Vol. 40 ( 12 ) page: 1411 - 1413   2011.12

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    Irradiation with a nanosecond pulse laser (lambda = 532 nm) was performed on spherical hollow silica particles modified with gold nanoparticles to photoexcite the localized surface plasmon resonance, resulting in the formation of pores on the shell wall accompanied with the fragmentation of the original Au particles to much smaller ones. The size of pores was tunable from 17 to 56 nm by varying the size of original Au particles on SiO2 shell from 6 to 39 nm.

    DOI: 10.1246/cl.2011.1411

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  92. Enhanced Photocurrent Generation in Layer-by-Layer-Assembled CdS Nanoparticle/Titania Nanosheet Multilayer Films Reviewed

    Kameyama Tatsuya, Okazaki Ken-ichi, Takagi Katsuhiko, Torimuto Tsukasa

    ELECTROCHEMISTRY   Vol. 79 ( 10 ) page: 776 - 778   2011.10

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  93. Enhanced Photocurrent Generation in Layer-by-Layer-Assembled CdS Nanoparticle/Titania Nanosheet Multilayer Films Reviewed

    Tatsuya Kameyama, Ken-ichi Okazaki, Katsuhiko Takagi, Tsukasa Torimuto

    ELECTROCHEMISTRY   Vol. 79 ( 10 ) page: 776 - 778   2011.10

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    Inorganic semiconductor multilayer thin films of CdS nanoparticles and titania nanosheet (TNS) were prepared by an electrostatic layer-by-layer accumulation technique. The absorbance of immobilized CdS and TNS linearly increased in proportion to the number of accumulated films, but the photoluminescence of CdS nanoparticles was dramatically quenched by being tucked into the TNS layer. Accumulation of the TNS/CdS layer remarkably enhanced the photocurrent generation compared to the case of films layer-by-layer-deposited with CdS nanoparticles and polystyrene sulfonate of an inert polymer. These observations can be explained by the efficient photoinduced electron transfer from photoexcited CdS nanoparticles to adjacent TNS layers.

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  94. Plasmon-Enhanced Photocatalytic Activity of Cadmium Sulfide Nanoparticle Immobilized on Silica-Coated Gold Particles Reviewed

    Tsukasa Torimoto, Hiroki Horibe, Tatsuya Kameyama, Ken-ichi Okazaki, Shigeru Ikeda, Michio Matsumura, Akira Ishikawa, Hajime Ishihara

    JOURNAL OF PHYSICAL CHEMISTRY LETTERS   Vol. 2 ( 16 ) page: 2057 - 2062   2011.8

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    Nanocomposite photocatalysts of CdS nanoparticles immobilized on Au core-SiO2 shell particles, in which the SiO2 layer acts as an insulator layer to prevent direct electron transfer from photoexcited CdS to Au particles, were prepared. The photocatalytic activity of CdS particles for H-2 evolution was greatly dependent on the distance between CdS and Au particles, due to the locally enhanced electric field produced by photoexcitation of the localized surface plasmon resonance (LSPR) peak of Au particles. Increase in Au core size enlarged the optimal distance between Au and CdS for the enhancement of photocatalysis. This behavior was theoretically reproduced by solving a self-consistent equation system, in which the range of energy dissipation became wider for larger diameter of the Au sphere, and then the balance with the enhancement of photoexcitation of CdS particles by the LSPR-induced electric field was changed.

    DOI: 10.1021/jz2009049

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  95. Surface-plasmon-enhanced photocurrent generation of CdTe nanoparticle/titania nanosheet composite layers on Au particulate films

    Tatsuya Kameyama, Yumi Ohno, Ken-ichi Okazaki, Taro Uematsu, Susumu Kuwabata, Tsukasa Torimoto

    JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY   Vol. 221 ( 2-3 ) page: 244 - 249   2011.6

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE SA  

    Multilayer films composed of Au particle/titania nanosheet (TNS)/CdTe nanoparticle were successfully prepared using a layer-by-layer-deposition technique. CdTe nanoparticles were accumulated as the topmost layer on TNS/poly(diallyldimethylammonium) (PDDA) bilayers deposited on the substrates of an Au particle film or an F-doped SnO2 (Fro) electrode. CdTe nanoparticles were acted as a photosensitizer. The photogenerated electrons in CdTe nanoparticles were injected into the conduction band of titania nanosheets to produce anodic photocurrent at a more positive potential than 0.4 V vs. Ag/AgCl. The magnitude of photocurrent was much larger for the films prepared on the Au particle film rather than that on the FTO electrode. Furthermore, with an increase in the thickness of (TNS/PDDA) bilayers, that is, the distance between Au and CdTe nanoparticles, the photocurrent was drastically decreased. The enhancement factor of photocurrent, defined as the ratio of the magnitude of photocurrent obtained with CdTe particle layer immobilized on Au layer to that on FTO, was varied from 2 to 10 by changing the wavelength of irradiation light. The broad peak at 520 nm appeared in the action spectrum of the enhancement factor and its profile roughly corresponded to the localized surface plasmon resonance peak of Au particle layer whose peak wavelength was ca. 540 nm. These facts indicated that the photoexcitation of the surface plasmon of Au particles, which produced a locally enhanced electric field near Au particle layer, played an important role in the increase in the photoexcitation probability of CdTe nanoparticles deposited as the topmost layer. (C) 2011 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jphotochem.2011.02.029

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  96. Plasmon-Enhanced Photocatalytic Activity of Cadmium Sulfide Nanoparticle Immobilized on Silica-Coated Gold Particles Reviewed

    T. Torimoto, H. Horibe, T. Kameyama, K. Okazaki, S. Ikeda, M. Matsumura, A. Ishikawa, H. Ishihara

    J. Phys. Chem. Lett.   Vol. 2   page: 2057-2062   2011

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  97. Enhanced Photocurrent Generation in Layer-by-layer-assembled CdS Nanoparticle/Titania Nanosheet Multilayer Films Reviewed

    T. Kameyama, K. Okazaki, K. Takagi, T. Torimoto

    Electrochemistry,   Vol. 10   page: 776-778   2011

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  98. Nanoscale Laser Processing of Hollow Silica Microbeads Assisted by Surface Plasmon Resonance of Gold Particles Reviewed

    K. Furukawa, T. Kameyama, K. Okazaki, T. Yako, M. Otsuki, Y. Tsuboi, T. Torimoto

    Chem. Lett.   Vol. 40   page: 1411-1413   2011

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  99. Preparation and Photoelectrochemical Properties of Densely Immobilized Cu2ZnSnS4 Nanoparticle Films Reviewed

    T. Kameyama, T. Osaki, K. Okazaki, T. Shibayama, A. Kudo, S. Kuwabata, T. Torimoto

    J. Mater. Chem.   Vol. 20   page: 5319-5324   2010

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  100. Size control and immobilization of gold nanoparticles stabilized in an ionic liquid on glass substrates for plasmonic applications Reviewed

    T. Kameyama, Y. Ohno, Takashi Kurimoto, K. Okazaki, T. Uematsu, S. Kuwabata, T. Torimoto

    Phys. Chem. Chem. Phys   Vol. 12   page: 1804-1811   2010

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  101. Surface-Plasmon-enhanced Photocurrent Generation of CdTe Nanoparticle/Titania Nanosheet Composite Layers on Au Particulate Films Reviewed

    T. Kameyama, Y. Ohno, K. Okazaki, T. Uematsu, S. Kuwabata, and T. Torimoto

    J. Photochem. Photobiol., A,   Vol. 221   page: 244-249   2010

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  102. Remarkable photoluminescence enhancement of ZnS-AgInS2 solid solution nanoparticles by post-synthesis treatment Reviewed

    T. Torimoto, S. Ogawa, T. Adachi, T. Kameyama, K. Okazaki, T. Shibayama, A. Kudo, S. Kuwabata

    Chem. Commun.,   Vol. 46   page: 2082-2084   2010

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  103. Preparation and photoelectrochemical properties of densely immobilized Cu2ZnSnS4 nanoparticle films

    Tatsuya Kameyama, Takaaki Osaki, Ken-ichi Okazaki, Tamaki Shibayama, Akihiko Kudo, Susumu Kuwabata, Tsukasa Torimoto

    JOURNAL OF MATERIALS CHEMISTRY   Vol. 20 ( 25 ) page: 5319 - 5324   2010

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ROYAL SOC CHEMISTRY  

    Colloidal Cu2ZnSnS4 (CZTS) nanoparticles with sizes of 5-6 nm that contain no highly toxic elements were successfully synthesized through thermal reactions of metal acetate and sulfur in high-temperature oleylamine solution. The reaction temperature was a key factor for the synthesis of CZTS nanoparticles: synthesis at temperatures higher than 240 degrees C gave a pure CZTS crystal phase, whereas a secondary phase of CuS was formed at reaction temperatures lower than 180 degrees C. Nanoparticles were successfully accumulated on ITO-coated or quartz glass substrates via layer-bylayer deposition using 1,2-ethanedithiol as a cross-linking agent. The resulting CZTS particle films exhibited a photoresponse similar to that of p-type semiconductor photoelectrodes in an aqueous solution containing Eu(NO3)(3) as an electron scavenger. Potentials of the valence band edge and conduction band edge were determined from the onset potential of the cathodic photocurrent to be +0.3 and -1.2 V vs. Ag/AgCl, respectively.

    DOI: 10.1039/c0jm00454e

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  104. Size control and immobilization of gold nanoparticles stabilized in an ionic liquid on glass substrates for plasmonic applications

    Tatsuya Kameyama, Yumi Ohno, Takashi Kurimoto, Ken-ichi Okazaki, Taro Uematsu, Susumu Kuwabata, Tsukasa Torimoto

    PHYSICAL CHEMISTRY CHEMICAL PHYSICS   Vol. 12 ( 8 ) page: 1804 - 1811   2010

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    Gold (Au) nanoparticles were prepared by sputter deposition of Au metal in an ionic liquid (IL) of 1-butyl-3-methylimidazolium hexafluorophosphate (BMI-PF6). The size of Au nanoparticles was increased from 2.6 to 4.8 nm by heat treatment at 373 K. The nanoparticles uniformly dispersed in the IL were densely immobilized on a glass substrate surface modified with a silane coupling agent having an imidazole functional group by spreading the Au particle IL solution on the substrates, followed by heat treatment at 373 K. The optical property of the thus-obtained films was tunable by controlling the size of Au nanoparticles in the IL and the degree of immobilization. An intense localized surface plasmon resonance (LSPR) peak was observed in each Au particle film, and the wavelength of the LSPR peak could be controlled by changing the size of nanoparticles in the IL solution before immobilization. Photoexcitation of the LSPR peak caused enhancement of the photoluminescence of CdTe nanoparticles immobilized on Au nanoparticle films, probably due to the locally enhanced electric field formed around Au nanoparticles.

    DOI: 10.1039/b914230d

    Web of Science

    Scopus

  105. Remarkable photoluminescence enhancement of ZnS-AgInS2 solid solution nanoparticles by post-synthesis treatment

    Tsukasa Torimoto, Shoji Ogawa, Tomohiro Adachi, Tatsuya Kameyama, Ken-ichi Okazaki, Tamaki Shibayama, Akihiko Kudo, Susumu Kuwabata

    CHEMICAL COMMUNICATIONS   Vol. 46 ( 12 ) page: 2082 - 2084   2010

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    The photoluminescence intensity of ZnS-AgInS2 solid solution nanoparticles was remarkably enhanced by increasing the heating temperature to 180 degrees C, above which the emission was simply diminished, while ZnS coating of the particles resulted in further enhancement of PL intensity, giving the highest quantum yield of ca. 80%.

    DOI: 10.1039/b924186h

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    Scopus

  106. Stacked-structure-dependent photoelectrochemical properties of CdS nanoparticles /layered double hydroxide (LDH) nanosheet multilayer films prepared by layer-by-layer accumulation Reviewed

    T. Kameyama, K. Okazaki, K. Takagi, T. Torimoto

    Phys. Chem. Chem. Phys.   Vol. 11   page: 5369-5376   2009

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  107. Stacked-structure-dependent photoelectrochemical properties of CdS nanoparticle/layered double hydroxide (LDH) nanosheet multilayer films prepared by layer-by-layer accumulation

    Tatsuya Kameyama, Ken-ichi Okazaki, Katsuhiko Takagi, Tsukasa Torimoto

    PHYSICAL CHEMISTRY CHEMICAL PHYSICS   Vol. 11 ( 26 ) page: 5369 - 5376   2009

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:ROYAL SOC CHEMISTRY  

    Inorganic multilayer films were prepared by layer-by-layer accumulation of positively charged layered double hydroxide (LDH) nanosheets and negatively charged CdS nanoparticles of different sizes. Nanoparticles were densely immobilized on LDH sheets to form a monolayer without coalescence into larger particles. The absorbance and photoluminescence intensity of immobilized CdS particles were enlarged with an increase in the accumulation number of the film. Hybrid films produced by accumulation of both monolayers of CdS particles (diameter: 5 nm) and those of smaller CdS particles (2.1 nm) exhibited characteristic photoluminescence spectra indicating the efficient energy transfer of photogenerated excitons from nanoparticle layers of smaller CdS particles to those of larger ones. LDH/CdS multilayers deposited on an F-doped SnO2 (FTO) electrode behaved as an n-type semiconductor photoelectrode in an acetonitrile solution regardless of the size of the CdS particles immobilized, but their efficiency for photocurrent generation was greatly dependent on the stacked structure of the films. Accumulation of CdS particles of 2.1 nm in diameter on pre-coated LDH/CdS layers of 5 nm-sized CdS particles on FTO remarkably enhanced the photocurrent intensity in comparison to that in the case of accumulation of these two kinds of CdS particles in the opposite sequence. These observations can be explained by photoinduced electron transfer and energy transfer along with the band gap gradient in the films.

    DOI: 10.1039/b902023c

    Web of Science

  108. Photoluminescence enhancement of ZnS-AgInS2 solid solution nanoparticles layer-by-layer-assembled in inorganic multilayer thin films Reviewed

    Tatsuya Kameyama, Ken-ichi Okazaki, Yuji Ichikawa, Akihiko Kudo, Susumu Kuwabata, Tsukasa Torimoto

    CHEMISTRY LETTERS   Vol. 37 ( 7 ) page: 700 - 701   2008.7

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    Multilayer films of layered double hydroxide (LDH) nano-sheets and semiconductor nanoparticles of ZnS-AgInS2 solid solution (ZAIS) or US were prepared by a layer-by-layer deposition technique. The photoluminescence properties were remarkably dependent on the stacked structure of the films owing to the energy transfer from US to ZAIS nanoparticles.

    DOI: 10.1246/cl.2008.700

    Web of Science

  109. Photoluminescence enhancement of ZnS-AgInS2 solid solution nanoparticles layer-by -layer-assembled in inorganic multilayer thin films Reviewed

    T. Kameyama, K. Okazaki, Y. Ichikawa, A. Kudo, S. Kuwabata, T. Torimot

    Chem. Lett.   Vol. 12   page: 700-701   2008

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  110. Pyrene-to-porphyrin excited singlet energy transfer in LBL-deposited LDH nanosheets Reviewed

    T. Yui, T. Kameyama, T. Sasaki, T. Torimoto, K. Takagi

    J. Porphyrins Phtalocyanines   Vol. 11   page: 428-433   2007

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  111. Pyrene-to-porphyrin excited singlet energy transfer in LBL-deposited LDH nanosheets Reviewed

    Yui Tatsuto, Kameyama Tatsuya, Sasaki Takayosi, Torimoto Tsukasa, Takagi Katsuhiko

    JOURNAL OF PORPHYRINS AND PHTHALOCYANINES   Vol. 11 ( 5-6 ) page: 428 - 433   2007

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  112. Pyrene-to-porphyrin excited singlet energy transfer in LBL-deposited LDH nanosheets Reviewed

    Tatsuto Yui, Tatsuya Kameyama, Takayosi Sasaki, Tsukasa Torimoto, Katsuhiko Takagi

    JOURNAL OF PORPHYRINS AND PHTHALOCYANINES   Vol. 11 ( 5-6 ) page: 428 - 433   2007

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:WORLD SCI PUBL CO INC  

    Nano-ordered hybrid films of layered double hydroxide (LDH) nanosheets and two types of anionic dye molecules, i.e. tetrakis(4-carboxyphenyl)porphyrin (TCPP) and 1,3,6,8-pyre-netetrasulfonic acid (PTSA), were prepared by a layer by-layer deposition (LBL) method. Photo-induced energy transfers (PET) between the PTSA and TCPP layers were investigated for two differently stacked structures of the TCPP/LDH/PTSA hybrid films, Le; (a) PTSA/LDH multilayers independently stacked on the TCPP/LDH multilayers to form (TCPP/LDH)(n)/(PTSA/LDH)(n) and (b) TCPP/ LDH and PTSA/LDH monolayers deposited alternately to form [(TCPP/LDH)/(PTSA/LDH)](n) hybrid films, which were both prepared by varying the successivie-and alternate stacking of-the (TCPP/LDH) and (PTSA/LDH) unit layers. A Foerster type resonance energy transfer is observed in the present hybrid films, where the efficiency of PET was strongly affected by changing the distance between the TCPP and PTSA molecules in the (TCPP/LDH)(3)/(PSS/LDH)(m)/(PTSA/LDH)(3) hybrid films (m = 1-10) obtained by the insertion of the photochemically inert poly (styrenesulfonic acid) (PSS) and LDH hybrid layers, i.e. the insertion of (PSS/LDH). between the (TCPP/LDH), and (PTSA/LDH), layers. Copyright (C) 2007 Society of Porphyrins & Phthalocyanines.

    DOI: 10.1142/S1088424607000485

    Web of Science

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Books 3

  1. 金属ナノ粒子の合成/構造制御とペースト化および最新応用展開

    鳥本司, 亀山達矢, 津田哲哉, 桑畑進( Role: Joint author ,  第2章 第2節 イオン液体/金属スパッタリング法による金属ナノ粒子の合成と機能材料への応用)

    株式会社R&D支援センター  2020.12  ( ISBN:978-4-905507-48-2

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    Total pages:354   Responsible for pages:27-46   Language:Japanese

  2. Photosynergetic Responses in Molecules and Molecular Aggregates

    Tsukasa Torimoto and Tatsuya Kameyama( Role: Joint author ,  Ch. 13 Controlling Optical Properties of Multinary Quantum Dots for Developing Novel Photoelectrochemical Reactions)

    Springer  2020.9 

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    Responsible for pages:223-237   Language:English

    DOI: 10.1007/978-981-15-5451-3_13

  3. "Top-Down Synthesis Methods for Nanoscale Catalysts" in Nanocatalysis in Ionic Liwuids

    T. Torimoto, T. Kameyama, S. Kuwabata( Role: Joint author)

    Wiley  2016 

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    Language:English Book type:Scholarly book

MISC 21

  1. Colloidal Synthesis of Ternary Ag-Bi-S Quantum Dots and the Control of Their Photochemical Properties

    秋吉一孝, ZHANG Wentao, 亀山達矢, 鳥本司

    電気化学秋季大会講演要旨集(CD-ROM)   Vol. 2021   2021

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  2. Improvement of Plasmonic TLC Performance for Precise Separation of Multinary Quantum Dots

    前田結衣, 山口奈緒子, 秋吉一孝, 亀山達矢, 坪井泰之, 石原一, 鳥本司

    電気化学秋季大会講演要旨集(CD-ROM)   Vol. 2021   2021

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  3. Preparation of Core-shell-structured Au@Ni Nanoparticles with Ionic Liquid/Metal Sputtering and Their Electrocatalytic Activity for Urea Oxidation

    伊藤由実, 秋吉一孝, 亀山達矢, 桑畑進, 鳥本司

    電気化学会東北支部セミコンファレンス・東北若手の会(CD-ROM)   Vol. 52nd   2021

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  4. Synthesis and electrocatalytic reactivity of AuRh alloy nanoparticles by ionic liquid/metal sputtering

    秋吉一孝, 秋吉一孝, 渡辺夢三, 亀山達矢, 川脇徳久, 桑畑進, 鳥本司, 鳥本司

    電気化学会大会講演要旨集(CD-ROM)   Vol. 88th   2021

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  5. Temperature Sensing with Photoluminescent AIGS@ZnGaS Core/Shell Quantum Dots

    都澤諒, 亀山達矢, 上松太郎, 宮地冬, 湯川博, 桑畑進, 馬場嘉信, 鳥本司

    電気化学秋季大会講演要旨集(CD-ROM)   Vol. 2021   2021

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  6. Syntheses and Photoelectrochemical Properties of Molybdenum Oxide Nanoparticles by Ionic Liquid/Metal Sputtering Technique

    秋吉一孝, 秋吉一孝, 亀山達矢, 桑畑進, 鳥本司, 鳥本司

    電気化学会大会講演要旨集(CD-ROM)   Vol. 87th   2020

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  7. Optical manipulation of nanoparticles in superfluid helium

    小門慶祐, 蓑輪陽介, 佐藤健太郎, 亀山達矢, 鳥本司, 芦田昌明

    光物性研究会論文集   Vol. 30th   2019

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  8. Rod-shaped Zn-Ag-In-Te nanocrystals with wavelength-tunable band-edge photoluminescence in the near-IR region

    Tatsuya Kameyama, Kouta Sugiura, Yujiro Ishigami, Takahisa Yamamoto, Susumu Kuwabata, Tomoki Okuhata, Naoto Tamai, Tsukasa Torimoto

    Journal of Materials Chemistry C   Vol. 6 ( 8 ) page: 2034 - 2042   2018

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    Language:English   Publishing type:Rapid communication, short report, research note, etc. (scientific journal)   Publisher:Royal Society of Chemistry  

    Rod-shaped nanocrystals (NCs) composed of ZnTe-AgInTe2 solid solution ((AgIn)xZn2(1-x)Te2, ZAITe) were synthesized in a 1-dodecanethiol solution. The resulting ZAITe NCs of 4-5 nm in width and 16-18 nm in length showed exciton peaks in the absorption spectra, regardless of their composition. The energy gap was enlarged from 1.2 to 1.6 eV by decreasing the x value of the NCs from 1.0 to 0.25. A sharp photoluminescence (PL) peak was observed in each PL spectrum of the NCs with x values of 1.0-0.5, assignable to band-edge emission, while NCs with x = 0.25 showed an additional broad PL peak originating from the defect sites due to the increased non-stoichiometry of NCs. With a decrease in x from 1.0 to 0.25, the band-edge PL peak was blue-shifted from 1010 to 809 nm in the near-IR region, accompanied by a decrease in the corresponding PL quantum yield from 47% to 0.07% due to the diminution of radiative recombination rate.

    DOI: 10.1039/c7tc05624a

    Scopus

  9. BIOINDUSTRY・NIR-II近赤外領域における移植幹細胞in vivo蛍光イメージング

    BIOINDUSTRY・NIR-II近赤外領域における移植幹細胞in vivo蛍光イメージング   Vol. 34 ( 1 ) page: 27 - 34   2017.1

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    Language:Japanese  

  10. 近赤外バイオイメージング-NIR-II:第2の生体の窓 NIR-II近赤外領域における移植幹細胞in vivo蛍光イメージング

    湯川博, 小林香央里, 湯川博, 小林香央里, 新岡宏彦, 亀山達矢, 佐藤和秀, 鳥本司, 石川哲也, 馬場嘉信, 馬場嘉信

    Bio Industry   Vol. 34 ( 1 )   2017

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  11. 生体イメージングを目指した近赤外発光性AgInTe<sub>2</sub>量子ドットの開発

    亀山達矢, 石神裕二郎, 湯川博, 嶋田泰佑, 馬場嘉信, 石川哲也, 桑畑進, 鳥本司

    日本化学会春季年会講演予稿集(CD-ROM)   Vol. 96th   2016

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  12. カドミウムフリー量子ドットを用いた生体内深部イメージング

    荻原裕佑, 湯川博, 小野島大介, 亀山達矢, 林由美, 鳥本司, 石川哲也, 馬場嘉信

    日本化学会春季年会講演予稿集(CD-ROM)   Vol. 96th   2016

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  13. NIR-II近赤外蛍光ナノ粒子による幹細胞イメージング手法の構築

    嶋田泰佑, 嶋田泰佑, 湯川博, 小野島大介, 新岡宏彦, 亀山達矢, 林由美, 鳥本司, 石川哲也, 馬場嘉信, 馬場嘉信, 馬場嘉信

    日本化学会講演予稿集   Vol. 95th ( 2 )   2015

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  14. 超低毒性量子ドットを用いた単一幹細胞ラベリングと3D in vivoイメージング

    荻原裕佑, 湯川博, 小野島大介, 亀山達矢, 林由美, 鳥本司, 石川哲也, 馬場嘉信, 馬場嘉信, 馬場嘉信

    日本化学会講演予稿集   Vol. 95th ( 2 )   2015

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  15. プルシアンブルーナノ粒子の紫外可視吸収スペクトルにおける多体効果

    渡邊真太, 澤田裕貴, 中谷真人, 吉野正人, 亀山達矢, 鳥本司, 稲葉優介, 高橋秀治, 竹下健二, 尾上順

    ナノ学会大会講演予稿集   Vol. 13th   2015

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  16. フェロシアン化物ナノ粒子のTEM構造解析

    増田秀樹, 稲葉優介, 高橋秀治, 竹下健二, 澤田裕貴, 中谷真人, 亀山達矢, 鳥本司, 尾上順

    ナノ学会大会講演予稿集   Vol. 13th   2015

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  17. フェロシアン化物ナノ粒子に対する金属イオン吸着機構に関する研究:(2)フェロシアン化物ナノ粒子の紫外可視吸収スペクトル解析

    澤田裕貴, 渡邊真太, 中谷真人, 吉野正人, 長崎正雅, 亀山達矢, 鳥本司, 尾上順, 稲葉優介, 高橋秀治, 竹下健二

    日本イオン交換研究発表会講演要旨集   Vol. 31st   2015

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  18. カドミウムフリー量子ドットを用いた幹細胞ラベリングの評価とin vivoイメージング

    荻原裕佑, 湯川博, 石神裕二郎, 吉住寧真, 中川伸吾, 大原倫美, 亀山達矢, 小野島大介, 鳥本司, 石川哲也, 馬場嘉信, 馬場嘉信, 馬場嘉信

    再生医療   Vol. 14   2015

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  19. Size- and Composition-controlled Syntheses of Metal Nanoparticle Composites Via Ionic Liquid/Metal Sputtering

      Vol. 58 ( 3 ) page: 111 - 118   2015

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    Language:Japanese  

    CiNii Books

  20. 半導体ナノ粒子の液相合成・固定化と光機能材料への応用 Invited

    鳥本 司, 笹村哲也, 亀山達矢, 岡崎健一

    光技術コンタクト   Vol. 49 ( 3 ) page: 11-17   2011.3

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  21. 半導体ナノ粒子の組織化と光機能: 量子ドット配列制御による高機能性材料の創製 Invited Reviewed

    亀山達矢, 鳥本 司

    化学と工業   Vol. 63 ( 4 ) page: 327-329 - 329   2010.4

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    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:日本化学会  

    CiNii Books

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Presentations 54

  1. Synthesis strategy of Ag-based multinary quantum dots from the perspective of controlling emission properties Invited

    Tatsuya Kameyama

    2022.3.26 

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    Event date: 2022.3

    Language:English   Presentation type:Oral presentation (invited, special)  

  2. Tuning the Energy Structure of Heterojunction in ZnS-AgInS2 Nanodumbbells by Cu Doping International conference

    T. Kameyama, S. Tsuneizumi, S. Kuwabata, T. Torimoto

    11thAsia Photochemistry Conference  2021.10.31 

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    Event date: 2021.10

    Language:English   Presentation type:Oral presentation (general)  

    Venue:Online  

  3. Composition-Controlled Synthesis of Near-IR-Light-Emitting Ag-In-Ga-Se Nanocrystals for Biological Imaging International conference

    T. Kameyama, H. Yamauchi, T. Mizumaki, H. Yukawa, Y. Baba, S. Kuwabata, T. Torimoto

    239th ECS Meeting  2021.6.1  Electrochemical society

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    Event date: 2021.6

    Language:English  

    Venue:Online  

  4. Wavelength-tunable Photoluminescence of Se-doped Ag-In-Ga-S Quantum Dots for In Vivo Imaging

    Nurmanita Rismaningsih, Hiroki Yamauchi, Tatsuya Kameyama, Hiroshi Yukawa, Yoshinobu Baba, Susumu Kuwabata, Tsukasa Torimoto

    2021.3 

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    Event date: 2021.3

    Language:English   Presentation type:Oral presentation (general)  

  5. ガルバニ置換反応により作製したAg-Ptナノリングの電極触媒活性と光照射効果

    太田 直希, 笹本 康介, 亀山 達矢, 鳥本 司

    電気化学会第88回大会  2021.3 

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    Event date: 2021.3

    Language:Japanese   Presentation type:Oral presentation (general)  

  6. CuドープによるAgInTe2量子ドットの近赤外発光波長制御

    武藤 千聖, 亀山 達矢, 桑畑 進, 鳥本 司

    電気化学会第88回大会  2021.3 

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    Event date: 2021.3

    Language:Japanese   Presentation type:Oral presentation (general)  

  7. Agナノ粒子を用いるプラズモンTLCの作製と量子ドットのサイズ分離への応用

    前田 結衣, 山口 奈緒子, 秋吉 一孝, 亀山 達矢, 坪井 泰之, 石原 一, 鳥本 司

    電気化学会第88回大会  2021.3 

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    Event date: 2021.3

    Language:Japanese   Presentation type:Oral presentation (general)  

  8. コア・シェル構造Ag-In-Ga-S量子ドットの水溶化と発光特性制御

    都澤 諒, 宮前 千恵, 亀山 達矢, 上松 太郎, 桑畑 進, 鳥本 司

    電気化学会第88回大会  2021.3 

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    Event date: 2021.3

    Language:Japanese   Presentation type:Oral presentation (general)  

  9. Ag-In-Ga-S 半導体量子ドットのコアシェル化による光触媒活性向上

    森 達哉, 亀山達矢, 上松太郎, 桑畑 進, 鳥本 司

    2020年度ヤングエレクトロケミスト研究会・光電気化学研究会  2020.12 

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    Event date: 2020.12

    Language:Japanese   Presentation type:Oral presentation (general)  

  10. ZnS-AgInS2-CuInS2ヘテロ構造ナノ粒子の組成変化によるエネルギー構造制御

    常泉修平, 亀山達矢, 桑畑 進, 鳥本 司

    2020年度ヤングエレクトロケミスト研究会・光電気化学研究会  2020.12 

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    Event date: 2020.12

    Language:Japanese   Presentation type:Oral presentation (general)  

  11. Promoting Hot Carrier Extraction in Zn-Ag-In-Te­ Nanocrystals By Irradiation of High-Energy Light International conference

    T. Kameyama, K. Sugiura, S. Kuwabata, T. Okuhata, N. Tamai and T. Torimoto

    Pacific RIM Meeting on Electrochemical and Solid State Science (PRiME2020)  2020.10 

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    Event date: 2020.10

    Language:English   Presentation type:Oral presentation (general)  

  12. Controlling Electronic Energy Structure of Ag-In-Ga-S-Se Quantum Dots Showing Band-Edge Emission International conference

    N. Rismaningsih, H. Yamauchi, T. Kameyama, T. Uematsu, S. Kuwabata, and T. Torimoto

    Pacific RIM Meeting on Electrochemical and Solid State Science (PRiME2020)  2020.10 

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    Event date: 2020.10

    Language:English   Presentation type:Poster presentation  

  13. プラズモニックAg-Ptナノリングの作製と酸素還元反応の電極触媒活性

    太田 直希, 笹本 康介, 亀山 達矢, 鳥本 司

    2020年光化学討論会  2020.9 

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    Event date: 2020.9

    Language:Japanese   Presentation type:Poster presentation  

  14. 八面体金ナノ粒子を内包するプラズモニック電極触媒の作製と光照射による活性向上

    坂部直人, 菅田 諒 , 亀山達矢, 鳥本 司

    第126回触媒討論会  2020.9 

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    Event date: 2020.9

    Language:Japanese   Presentation type:Oral presentation (general)  

  15. ダンベル形状ZnS-AgInS2-CuInS2 ナノ粒子の組成変化による光化学特性制御

    常泉 修平,亀山 達矢,桑畑 進,鳥本 司

    第71回コロイドおよび界面化学討論会  2020.9 

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    Event date: 2020.9

    Language:Japanese   Presentation type:Oral presentation (general)  

  16. 光触媒活性向上のためのAg-In-Ga-S 半導体量子ドットのナノ構造制御

    森 達哉,亀山 達矢,上松 太郎,桑畑 進,鳥本 司

    第71回コロイドおよび界面化学討論会  2020.9 

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    Event date: 2020.9

    Language:Japanese   Presentation type:Oral presentation (general)  

  17. GaSx被覆Ag-In-Ga-Se量子ドットの表面処理による近赤外発光特性の向上

    武藤 千聖, 山内 弘樹, 亀山 達矢, 上松 太郎, 桑畑 進, 鳥本 司

    2020年光化学討論会  2020.9 

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    Event date: 2020.9

    Language:Japanese   Presentation type:Poster presentation  

  18. 銀ナノ粒子による多元量子ドットのプラズモントラッピングとサイズ分離

    前田 結衣, 山口 奈緒子, 秋吉 一孝, 亀山 達矢, 東海林 竜也, 坪井 泰之, 石原 一, 鳥本 司

    2020年光化学討論会  2020.9 

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    Event date: 2020.9

    Language:Japanese   Presentation type:Oral presentation (general)  

  19. 水溶性Ag-In-Ga-S量子ドットの合成と光学特性制御

    都澤 諒, 宮前 千恵, 亀山 達矢, 桑畑 進, 鳥本 司,

    2020年光化学討論会  2020.9 

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    Event date: 2020.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:オンライン  

  20. Enhancement of Electrocatalytic Oxygen Reduction Reaction on Au-Ag nanorings by Plasmon Excitation International conference

    Tatsuya Kameyama, Kosuke Sasamoto, Tsukasa Torimoto

    The 7th Optical Manipulation Conference(OMC’2020)  2020.4 

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    Event date: 2020.4

    Language:English   Presentation type:Poster presentation  

  21. Near-IR Sensitization of ZnO Rod Electrode by Non-toxic Ag8SnS6 Nanoparticles International conference

    T. Kameyama, S. Fujita, H. Furusawa and Tsukasa Torimoto

    Electrochemical Society 

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    Event date: 2014.5

    Language:English   Presentation type:Oral presentation (general)  

    Country:United States  

  22. Preparation of Novel Near-Infrared Light-Responsive Ag8SnS6 Quantum Dots for Photovoltaic Device International conference

    T. Kameyama, S. Fujita, H. Furusawa, T. Torimoto

    The 14 th International Symposium on Biomimetic Materials Processing 

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    Event date: 2014.1

    Language:English   Presentation type:Oral presentation (invited, special)  

    Country:Japan  

  23. Synthesis and Photoelectrochemical Characterization of Ag-based Multinary Semiconductor Nanoparticles for Solar Energy Conversion

    T. Kameyama, Y. Douke, T. Torimoto

    The 2nd Seminar on Future Vision of Green Mobility and Advance Technologies for Realizing the Vision 

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    Event date: 2013.12

    Language:English   Presentation type:Oral presentation (invited, special)  

    Country:Thailand  

  24. Preparation and Photoelectrochemical Properties of ZnSe-AgInSe2 Solid Solution Nanoparticles for Quantum Dot Solar Cells International conference

    Tatsuya Kameyama, Yusuke Douke, Susumu Kuwabata, Tsukasa Torimoto

    IMSE-7 

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    Event date: 2013.9

    Language:English   Presentation type:Oral presentation (invited, special)  

    Country:China  

  25. Synthesis of Ternary Ag-Sn-S Colloidal Nanoparticles for Photoenergy Conversion System

    T. Kameyama, S. Fujita, T. Sasamura, T. Torimoto

    International Photochemistry Conference 

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    Event date: 2013

    Language:English   Presentation type:Poster presentation  

    Country:Belgium  

  26. ZnS-CuInS2-AgInS2固溶体ナノ結晶の形状およびエネルギーギャップ制御 International conference

    戴美林, 亀山達矢, 桑畑進, 鳥本司

    日本化学会 

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    Event date: 2013

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  27. Ag8SnS6 ナノ粒子の作製と光電気化学特性

    藤田繁稔, 笹村哲也, 亀山達矢, 桑畑進, 鳥本司

    電気化学会 

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    Event date: 2013

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  28. Photoelectrochemical Properties of ZnO Porous Electrodes Modified with Non-stoichiometric Ag-In-S Semiconductor Nanoparticles

    Menéndez-Flores Victor. M., Dai Meilin, Kameyama Tatsuya, Kuwabata Susumu, Ttorimoto Tsukasa

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    Event date: 2013

    Language:English   Presentation type:Oral presentation (general)  

    Country:Japan  

  29. Fabrication and Photoelectrochemical Properties of AgInS2 Quantum Dots Deposited on TiO2 Electrode Using a SILAR Technique

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    Event date: 2013

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  30. Dependence of Photoelectrochemical Properties of LDH Nanosheet/CdS Nanoparticle Multilayer Films on Their Stacked Structure International conference

    T. Kameyama, T. Osaki, K. Okazaki, T. Shibayama, A. Kudo, S. Kuwabata, T. Torimoto

    18th International Conference on Photochemical Conversion and Storage of Solar Energy 

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    Event date: 2010

    Language:English   Presentation type:Poster presentation  

    Country:Korea, Republic of  

  31. Dependence of Photoelectrochemical Properties of LDH Nanosheet/CdS Nanoparticle Multilayer Films on Their Stacked Structure International conference

    T. Kameyama, K. Okazaki, T. Torimoto

    217th Electrochemical Society Meeting 

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    Event date: 2010

    Language:English   Presentation type:Oral presentation (general)  

    Country:Canada  

  32. Photoelectrochemical Properties of Cu2ZnSnS4 Nanoparticles Film Prepared via Layer-by-layer Deposition International conference

    T. Kameyama, T. Osaki, K. Okazaki, T. Shibayama, S. Kuwabata, T. Torimoto

    International Conference on Nanoscopic Colloid and Surface Science 2010 

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    Event date: 2010

    Language:English   Presentation type:Poster presentation  

    Country:Japan  

  33. Stacked-structure-dependent Photocurrent Generation in LDH/CdS Multilayer Thin Films International conference

    T. Kameyama, K. Okazaki, T. Torimoto

    24th International Conference on Photochemistry 

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    Event date: 2009.7

    Language:English   Presentation type:Poster presentation  

    Country:Spain  

  34. Photochemical Properties of Highly Luminescent ZnS-AgInS2 Solid Solution Nanoparticles International conference

    T. Torimoto, T. Kameyama, T. Adachi, K. Okazaki, A. Kudo, S. Kuwabata

    24th International Conference on Photochemistry 

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    Event date: 2009

    Language:English   Presentation type:Oral presentation (general)  

    Country:Japan  

  35. Efficient Photocurrent Generation in Multilayer Thin Films of LDH Nanosheets and CdS Nanoparticles International conference

    T. Kameyama, K. Okazaki, T. Torimoto,

    4th International Symposium on Integrated Molecular/Materials Engineering 

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    Event date: 2009

    Language:English   Presentation type:Oral presentation (invited, special)  

    Country:China  

  36. Photoluminescence of Layer-by-layer- assembled Semiconductor Nanoparticle-LDH Nanosheet Hybrid Films International conference

    T. Kameyama, K. Okazaki, Y. Ichikawa, A. Kudo, S. Kuwabata, T. Torimoto

    XXIInd IUPAC Symposium on Photochemistry 

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    Event date: 2008

    Language:English   Presentation type:Poster presentation  

    Country:United States  

  37. Photochemical Properties of ZnS-AgInS2 Solid Solution Nanoparticles in Layer-by- layer-assembled Hybrid Films International conference

    T. Kameyama, K. Okazaki, Y. Ichikawa, A. Kudo, S. Kuwabata, T. Torimoto

    PRiME 2008 Joint Internatinal Meeting 

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    Event date: 2008

    Language:English   Presentation type:Poster presentation  

    Country:Sweden  

  38. Ag8SnS6 ナノ粒子の作製と光電気化学特性 International conference

    藤田繁稔, 笹村哲也, 亀山達矢, 桑畑進, 鳥本司

    電気化学会  2013 

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    Language:Japanese   Presentation type:Oral presentation (general)  

  39. ZnS-CuInS2-AgInS2固溶体ナノ結晶の形状およびエネルギーギャップ制御

    戴美林, 亀山達矢, 桑畑進, 鳥本司

    日本化学会  2013 

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    Language:Japanese   Presentation type:Oral presentation (general)  

  40. Synthesis of Ternary Ag-Sn-S Colloidal Nanoparticles for Photoenergy Conversion System International conference

    T. Kameyama, S. Fujita, T. Sasamura, T. Torimoto

    International Photochemistry Conference  2013 

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    Language:English   Presentation type:Poster presentation  

  41. Synthesis and Photoelectrochemical Characterization of Ag-based Multinary Semiconductor Nanoparticles for Solar Energy Conversion International conference

    T. Kameyama, Y. Douke, T. Torimoto

    The 2nd Seminar on Future Vision of Green Mobility and Advance Technologies for Realizing the Vision  2013.12.2 

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    Language:English   Presentation type:Oral presentation (invited, special)  

  42. Stacked-structure-dependent Photocurrent Generation in LDH/CdS Multilayer Thin Films

    T. Kameyama, K. Okazaki, T. Torimoto

    24th International Conference on Photochemistry  2009.7 

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    Language:English   Presentation type:Poster presentation  

  43. Fabrication and Photoelectrochemical Properties of AgInS2 Quantum Dots Deposited on TiO2 Electrode Using a SILAR Technique International conference

    2013 

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    Language:Japanese   Presentation type:Oral presentation (general)  

  44. Preparation of Novel Near-Infrared Light-Responsive Ag8SnS6 Quantum Dots for Photovoltaic Device

    T. Kameyama, S. Fujita, H. Furusawa, T. Torimoto

    The 14 th International Symposium on Biomimetic Materials Processing  2014.1.24 

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    Language:English   Presentation type:Oral presentation (invited, special)  

  45. Preparation and Photoelectrochemical Properties of ZnSe-AgInSe2 Solid Solution Nanoparticles for Quantum Dot Solar Cells

    Tatsuya Kameyama, Yusuke Douke, Susumu Kuwabata, Tsukasa Torimoto

    IMSE-7  2013.9.19 

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    Language:English   Presentation type:Oral presentation (invited, special)  

  46. Photoluminescence of Layer-by-layer- assembled Semiconductor Nanoparticle-LDH Nanosheet Hybrid Films

    T. Kameyama, K. Okazaki, Y. Ichikawa, A. Kudo, S. Kuwabata, T. Torimoto

    XXIInd IUPAC Symposium on Photochemistry  2008 

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    Language:English   Presentation type:Poster presentation  

  47. Photoelectrochemical Properties of ZnO Porous Electrodes Modified with Non-stoichiometric Ag-In-S Semiconductor Nanoparticles International conference

    Menéndez-Flores Victor. M, Dai Meilin, Kameyama Tatsuya, Kuwabata Susumu, Ttorimoto Tsukasa

    2013 

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    Language:English   Presentation type:Oral presentation (general)  

  48. Photoelectrochemical Properties of Cu2ZnSnS4 Nanoparticles Film Prepared via Layer-by-layer Deposition

    T. Kameyama, T. Osaki, K. Okazaki, T. Shibayama, S. Kuwabata, T. Torimoto

    International Conference on Nanoscopic Colloid and Surface Science 2010  2010 

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    Language:English   Presentation type:Poster presentation  

  49. Photochemical Properties of ZnS-AgInS2 Solid Solution Nanoparticles in Layer-by- layer-assembled Hybrid Films

    T. Kameyama, K. Okazaki, Y. Ichikawa, A. Kudo, S. Kuwabata, T. Torimoto

    PRiME 2008 Joint Internatinal Meeting  2008 

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    Language:English   Presentation type:Poster presentation  

  50. Photochemical Properties of Highly Luminescent ZnS-AgInS2 Solid Solution Nanoparticles

    T. Torimoto, T. Kameyama, T. Adachi, K. Okazaki, A. Kudo, S. Kuwabata

    24th International Conference on Photochemistry  2009 

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    Language:English   Presentation type:Oral presentation (general)  

  51. Near-IR Sensitization of ZnO Rod Electrode by Non-toxic Ag8SnS6 Nanoparticles

    T. Kameyama, S. Fujita, H. Furusawa, Tsukasa Torimoto

    Electrochemical Society  2014.5.12 

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    Language:English   Presentation type:Oral presentation (general)  

  52. Efficient Photocurrent Generation in Multilayer Thin Films of LDH Nanosheets and CdS Nanoparticles

    T. Kameyama, K. Okazaki, T. Torimoto

    4th International Symposium on Integrated Molecular/Materials Engineering  2009 

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    Language:English   Presentation type:Oral presentation (invited, special)  

  53. Dependence of Photoelectrochemical Properties of LDH Nanosheet/CdS Nanoparticle Multilayer Films on Their Stacked Structure

    T. Kameyama, T. Osaki, K. Okazaki, T. Shibayama, A. Kudo, S. Kuwabata, T. Torimoto

    18th International Conference on Photochemical Conversion and Storage of Solar Energy  2010 

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    Language:English   Presentation type:Poster presentation  

  54. Dependence of Photoelectrochemical Properties of LDH Nanosheet/CdS Nanoparticle Multilayer Films on Their Stacked Structure

    T. Kameyama, K. Okazaki, T. Torimoto

    217th Electrochemical Society Meeting  2010 

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    Language:English   Presentation type:Oral presentation (general)  

▼display all

KAKENHI (Grants-in-Aid for Scientific Research) 8

  1. 傾斜構造による量子ドット内エネルギー勾配形成と電荷分離の促進

    Grant number:22H01906  2022.4 - 2025.3

    JSPS  科学研究費助成事業  基盤研究(B)

    亀山達矢

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    Authorship:Principal investigator  Grant type:Competitive

  2. バンド端-欠陥型近赤外蛍光量子ドット開発による生体深部温度イメージング計測の実現

    Grant number:22560533  2022.4 - 2025.3

    JSPS  科学研究費助成事業  基盤研究(B)

    湯川博、須賀英隆、亀山達矢

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    Authorship:Coinvestigator(s) 

  3. Preparation of Multinary Alloy Nanostructures via Non-equilibrium Processes and Their Electrocatalytic Activities

    Grant number:18H03927  2018.4 - 2022.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (A)

    Tsukasa Torimoto

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    Authorship:Coinvestigator(s)  Grant type:Competitive

    Alloy nanoparticles composed of multinary elements are expected to exhibit various functions. The preparation of multinary alloy nanoparticles, however, has been very difficult with use of conventional methods, because it requires more precise controls of the particle composition and size as the number of constituent metal elements increases. In this study, we used a non-equilibrium process, that is, an ionic liquid/metal sputtering method, to synthesize nanoparticles composed of non-equilibrium alloys, which were difficult to be prepared by conventional chemical methods. Furthermore, we evaluated electrocatalytic activities of obtained multinary alloy nanoparticles for various electrode reactions, in which the activities were strongly dependent on the particle compositions. Since our methods enable to obtain novel non-equilibrium alloy nanoparticles, we can use these to develop novel highly functional electrocatalysts.

  4. Stacking Structure-dependent Photovoltaic Performance of Multilayer Thin Films Composed of Multinary Solid Solution Quantum Dots

    Grant number:16H06052  2016.4 - 2019.3

    Kameyama Tatsuya

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    Authorship:Principal investigator 

    Grant amount:\26000000 ( Direct Cost: \20000000 、 Indirect Cost:\6000000 )

    Research on quantum dot solar cells is currently actively conducted around the world for the efficient use of solar energy. In this study, we changed the composition of solid solution type quantum dots such as ZnSe-AgInSe2 and prepared the quantum dot thin film structure while controlling the arrangement of energy gap of them. As a result, excitons were collected on the charge separation interface of the thin film via energy transfer, and the photoenergy conversion efficiency were improved by the exciton collection mechanism along the gradient of the energy gap. Such a system is expected to approach the high theoretical conversion efficiency of quantum dot solar cells.

  5. Efficient light energy conversion with semiconductor nano-photodiode particles

    Grant number:15H03876  2015.4 - 2018.3

    Torimoto Tsukasa

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    Authorship:Coinvestigator(s)  Grant type:Competitive

    Light energy conversion systems using semiconductor nanoparticles have been attracted much attention. In this study, we synthesized multinary semiconductor nanoparticles of low toxicity with solution phase methods and investigated their activities for light energy conversion. The photocatalytic activity of the ZnS-AgInS2 solid solution (ZAIS) nanoparticles was remarkably varied, depending on their particle composition, size, and shape. In particular, dumbbell-shaped ZAIS particles, composed of two ellipsoidal nanocrystals deposited on a rod-shaped particle, showed higher photocatalytic activity than those of single-component counterparts, due to the efficient charge separation at Type II heterojunction inside a particle. Furthermore, thin film photoelectrodes, composed of in the ZnTe-AgIgTe2 solid solution (ZAITe) nanoparticles, exhibited higher activity for photocurrent generation when the heterojunction was formed by the deposition of In2S3 shell layer on the ZAITe film surface.

  6. Electrocatalytic Activity of Orientated Metal Nanoparticles

    Grant number:15K13668  2015.4 - 2017.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Challenging Exploratory Research

    Kameyama Tatsuya

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    Authorship:Principal investigator 

    Grant amount:\3900000 ( Direct Cost: \3000000 、 Indirect Cost:\900000 )

    Octahedral Au-core Pt-shell (Au@Pt) nanoparticles were successfully prepared via a galvanic replacement of Cu monolayer underpotentially deposited on Au core with a Pt monolayer. Thus-obtained octahedral Au@Pt nanoparticles showed larger electrocatalytic activity for oxygen reduction reaction compared with spherical Au@Pt or commercial Pt nanoparticles. The visible light irradiation to Au@Pt nanoparticles-immobilized electrodes enlarged a cathodic current of oxygen reduction reaction, suggesting that the electrocatalytic activity of Pt shell layer was enhanced by the photoexcitation of localized surface plasmon resonance peak of octahedral Au-core particles

  7. Enhancement of photocurrent generation in quantum dot-sensitized solar cells by the collection of excitation energy

    Grant number:25810133  2013.4 - 2015.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists (B)

    KAMEYAMA Tatsuya

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    Authorship:Principal investigator 

    Grant amount:\4420000 ( Direct Cost: \3400000 、 Indirect Cost:\1020000 )

    Size-quantized semiconductor nanocrystals, so-called quantum dots (QDs), have attracted much attention for the application of light energy conversion systems. For the purpose of solar cell application, it is expected that the control of their arrangement of QDs, that is stuck structure of QDs, will improve the energy conversion efficiency of the cells because a preferable energy gradient can be obtained to drive the photogenerated electrons in semiconductor QDs array toward the collecting electrode.
    In this study, I tried to achieve that by the development of ZnSe-AgInSe2 solid solution QDs having widely-controllable-electronic-energy structure. Thus-prepared QDs were assembled onto electrode using dip-coating technique and investigated the electronic energy structures-related photocurrent generation.

  8. 電子エネルギー構造を自在に制御したナノ結晶集積膜の作製と光デバイスへの応用

    Grant number:09J09609  2009 - 2010

    日本学術振興会  科学研究費助成事業  特別研究員奨励費

    亀山 達矢

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    半導体ナノ粒子やナノシートなどのナノ結晶は、そのサイズや形状に依存して特異な光機能性を示すことから、光エネルギー変換材料への応用が試みられている。デバイス応用に際して、それらは主にスピンコートなどにより、マトリクス中に均一に分散した状態で用いられる。本研究では交互吸着法を用いて、これらナノ結晶を配列よく積層し、ナノオーダーでのエネルギー傾斜構造を構築することにより、高効率な光エネルギー変換材料の開発を行った。
    本年度の研究ではまず、効率的な光エネルギー変換を達成するため、バルク材料において高い光活性を示し、環境調和型の半導体材料として注目されているCu_2ZnSnS_4(CZTS)のナノ粒子化を試みた。各金属酢酸塩と硫黄粉末を、オレイルアミン中、240℃以上で加熱撹拌することで、ケステライト型結晶構造を有する、5-7nmのCZTSナノ粒子を合成することができた。このように合成したCZTSナノ粒子と、チタニアナノシートとを交互吸着法を用いて配列させることにより、膜内部に連続的なエネルギー傾斜構造を構築した。この交互積層膜を光活性層として、電子・正孔の輸送層や電極を取り付けることで、薄膜太陽電池を作製したところ、傾斜構造を構築していない場合と比較して、短絡電流値、開放端電圧値ともに倍以上の特性が発現することがわかった。このことはCZTS粒子/チタニアナノシートが形成する多層の電荷分離界面が、CZTS中に光生成したキャリアの取り出しを促進するためであると考えられる。
    以上のように、本研究で得られた知見は、半導体ナノ粒子の太陽電池など、光デバイスへの応用において、非常に有用なものである。高品質な粒子を作製し、さらにそれらの物質をうまく配列(組織化)させ、電子的・エネルギー的な相互作用を最大限に引き出すことができれば、材料の特性の向上や新しい機能の発現につながることを示した。

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Industrial property rights 2

  1. テルル化化合物ナノ粒子及びその製法

    鳥本司, 馬場嘉信, 亀山達矢, 石神裕二郎

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    Application no:2014-068504  Date applied:2014.3

    Country of applicant:Domestic  

  2. テルル化化合物ナノ粒子及びその製法

    鳥本司, 馬場嘉信, 亀山達矢, 石神裕二郎

     More details

    Application no:2014-068504  Date applied:2014.3

 

Teaching Experience (On-campus) 16

  1. 化学生命工学実験1

    2022

  2. 化学生命工学実験1

    2021

  3. 化学生命工学実験4

    2021

  4. 物理化学実験

    2016

  5. 無機物理化学演習第二

    2016

  6. 無機物理化学実験

    2016

  7. 無機物理化学実験

    2015

  8. 物理化学実験

    2015

  9. 無機物理化学演習第二

    2015

  10. 無機物理化学実験

    2014

  11. 無機物理化学演習第二

    2014

  12. 物理化学実験

    2014

  13. 無機物理化学実験

    2013

  14. 無機物理化学演習第二

    2013

  15. 物理化学実験

    2013

  16. 無機物理化学実験

    2012

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Social Contribution 1

  1. 2021年 豊西総合大学(出前授業)

    Role(s):Lecturer

    愛知県立豊田西高等学校  2021.11