Faculty Profiles - MATSUO Yutaka

Reducing-Agent-Free Barton–Kellogg Synthesis of Bis(fluorenylidene)quinacridanes with Chromic and NIR Absorption Properties Invited Reviewed Open Access

Xue-Lin Zheng, Shinobu Aoyagi, Yutaka Matsuo

Organic Letters Vol. 27 ( 30 ) page： 8321 - 8325 2025.7

Water-Soluble Fullerene Derivatives as Radical Scavengers for Highly Durable Proton Exchange Membrane Fuel Cells Reviewed Open Access

Ratna Balgis, Hibiki Ohashi, Kazuhira Miwa, Yoshiki Ono, Shoei Suyama, Takeshi Yanai, Miftakhul Huda, Takashi Watanabe, Tsutomu Aoki, Toshikazu Ogino, Chunyan Li, Masaya Kawasumi, Yutaka Matsuo

Communications Materials Vol. 6 page： 136 2025.7

Nitrogen-Containing Carbon-Encapsulated Platinum Electrocatalysts Supported by Single-Walled Carbon Nanotubes for Polymer Electrolyte Fuel Cells Reviewed International journal Open Access

Qiao Chen, Chu‐Yang Yu, Yong‐Chang Zhai, Takashi Watanabe, Masaya Kawasumi, Miftakhul Huda, Yutaka Matsuo

Small Methods 2025.4

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

白金（Pt）ベースの電気触媒は、固体高分子形燃料電池（PEFC）における酸素還元反応（ORR）の好ましい選択肢として広く認識されています。しかし、その安定性の低さは依然として重大な課題です。この問題を解決するために、強化直接注入熱分解合成（e-DIPS）法で製造された高結晶性・高純度の単層カーボンナノチューブ（SWCNT）を担体として利用し、窒素導入処理を施すことで窒素含有SWCNT（N-SWCNT）が製造されます。アモルファスカーボンシェルでカプセル化された白金電気触媒は、簡便で工業的に好ましい溶液プラズマ（SP）法を用いて窒素含有単層カーボンナノチューブ（Pt/N-SWCNT）上に合成されます。高解像度透過型電子顕微鏡観察により、Pt/N-SWCNT中のPtナノ粒子は窒素含有カーボンシェルでカプセル化されていることが示されました。単セルの膜電極接合体（MEA）のカソード触媒としてPt/N-SWCNT-MEAを用いた場合、加速耐久試験（ADT）16,000サイクル後でも最大出力密度はわずか20.8%しか低下しません。高電圧加速（1.0～1.5 V）後も、Pt/N-SWCNT-MEAの最大出力密度の低下は39.5%と、Pt/SWCNT-MEAの48.3%、市販のPt/Cの93.2%と比較して低い値を示しています。これらの結果は、窒素含有カーボンシェルとSWCNTを担体として用いることで、触媒の安定性と活性が向上し、PEFCの優れた性能につながっていることを示しています。

DOI： 10.1002/smtd.202500074

Open Access

Reaction Mechanism with Indano[60]fullerene Bromide for Evaporable Fullerene Derivatives Reviewed

PubMed

Spray-coated Carbon Nanotubes as Alternatives to ITO Electrodes for Inverted Perovskite Solar Cells Reviewed Open Access

Naoki Ueoka, Mizuki Yagisawa, Hisayoshi Oshima, Kimitaka Higuchi, Yoshimasa Hijikata, Masahiro Matsunaga, Yutaka Ohno, Hao-Sheng Lin, Yutaka Matsuo

Japanese Journal of Applied Physics Vol. 64 page： 04SP38 2025.4

Fabrication of Elastic Color-Changing Films—Elastomer Films Incorporating Mechanochromic Fluorenylidene–Acridane Open Access

Koki Iwasaki, Yutaka Matsuo

Molecules 2025.4

Low-Temperature Synthesis of Weakly Confined Carbyne Inside Single-Walled Carbon Nanotubes Reviewed International coauthorship

Bo-Wen Zhang, Xi-Yang Qiu, Yicheng Ma, Qingmei Hu, Aina Fitó-Parera, Ikuma Kohata, Ya Feng, Yongjia Zheng, Chiyu Zhang, Yutaka Matsuo, YuHuang Wang, Shohei Chiashi, Keigo Otsuka, Rong Xiang, Dmitry I. Levshov, Sofie Cambré, Wim Wenseleers, Slava V. Rotkin, Shigeo Maruyama

ACS Nano Vol. 19 ( 13 ) page： 12996 - 13006 2025.3

Hirofumi Amada, Yong-Chang Zhai, Koki Yamanaka, Qing-Jun Shui, Kin-ichi Oyama, Kazuhira Miwa, Hao-Sheng Lin, Yutaka Matsuo

Chemical Communications Vol. 61 ( 8 ) page： 1665 - 1668 2025.1

Heptamethine Cyanine Dye-Doped Single-Walled Carbon Nanotube Electrodes for Improving Performance of HTL-Free Perovskite Solar Cells Invited Reviewed International coauthorship

Man-Ge Cai, Arina Watanabe, Zhenyu Xu, Yong-Chang Zhai, Achmad Syarif Hidayat, Naoki Ueoka, Miftakhul Huda, Kimitaka Higuchi, Esko I. Kauppinen, Kazumasa Funabiki, Yutaka Matsuo

Molecules Vol. 30 ( 1 ) page： 60 2025.1

Facile Doping of 2,2,2-Trifluoroethanol to Single-Walled Carbon Nanotubes Electrodes for Durable Perovskite Solar Cells Reviewed

Naoki Ueoka, Achmad Syarif Hidayat, Hisayoshi Oshima, Yoshimasa Hijikata, Yutaka Matsuo

Photochem Vol. 4 ( 3 ) page： 319 - 333 2024.9

Hydrophobic Evaporable Fullerene Indanone Ketone with Low Sublimation Temperature and Amorphous Morphology for Inverted Perovskite Solar Cells Reviewed

Yong-Chang Zhai, Koki Yamanaka, Chu-Yang Yu, Jun-Zhuo Wang, Xue-Lin Zheng, Miftakhul Huda, Naoyuki Imai, Takeshi Igarashi, Shinobu Aoyagi, Yutaka Matsuo

Chemical Communications Vol. 60 ( 70 ) page： 9420 - 9423 2024.8

Synthesis of Indano[60]fullerene Thioketone and Its Application in Organic Solar Cells Invited Reviewed Open Access

Yong-Chang Zhai, Shimon Oiwa, Shinobu Aoyagi, Shohei Ohno, Tsubasa Mikie, Jun-Zhuo Wang, Hirofumi Amada, Koki Yamanaka, Kazuhira Miwa, Naoyuki Imai, Takeshi Igarashi, Itaru Osaka, Yutaka Matsuo

Beilstein Journal of Organic Chemistry Vol. 20 page： 1270 - 1277 2024.5

Color-Changing Paper: Cellulose Nanofiber Films Incorporating Mechanochromic Fluorenylidene-Acridane Reviewed International journal Open Access

Keisuke Ogumi, Takehiro Arakawa, Bungo Okudera, Yuki Takimoto, Kohki Nagata, Kentaro Mishiba, Eiji Abe, Tomonaga Ueno, Junko Hieda, Kenji Omote, Hao-Sheng Lin, Yutaka Matsuo

ACS Applied Engineering Materials Vol. 2 ( 2 ) page： 397 - 403 2024.1

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：American Chemical Society

Color-changing paper using a cellulose nanofiber (CNF) film with mechanical pressure-sensing capability was produced using mechanochromic fluorenylidene-acridane (FA), which exhibits color change upon mechanical pressure. This flexible film exhibits a visible color change from yellow to green in response to a mechanical force. Surface investigations, such as scanning electron microscopy and contact angle analysis, revealed that the repeatability of the color change was dependent on the CNF diameter. Furthermore, the FA-CNF film exhibited a linear response to mechanical pressure within the range of 25–300 MPa, as quantitatively measured by mechanochromism using a combination of nanoimprint testing and UV–vis spectroscopy. This measurement suggested that the flexibility of the film improved mechanochromic sensitivity. When compared with the conventional method using UV–vis spectroscopy, a simpler image processing method employing CYM color analysis was able to visualize the distribution of the mechanical pressure.

DOI： 10.1021/acsaenm.3c00702

Open Access

Evaporable Fullerene Indanones with Controlled Amorphous Morphology as Electron Transporters for Inverted Perovskite Solar Cells Reviewed International coauthorship Open Access

Qing-Jun Shui, Shiqi Shan, Yong-Chang Zhai, Shinobu Aoyagi, Seiichiro Izawa, Miftakhul Huda, Chu-Yang Yu, Lijian Zuo, Hongzheng Chen, Hao-Sheng Lin, Yutaka Matsuo

Journal of the American Chemical Society Vol. 145 ( 50 ) page： 27307 - 27315 2023.12

Single-walled Carbon Nanotubes Supported Pt Electrocatalyst as Cathode Catalyst of a Single Fuel Cell with High Durability Against Start-up/Shut-down Potential Cycling Reviewed Open Access

Miftakhul Huda, Tomoya Kawahara, Jae-Hyeok Park, Masaya Kawasumi, Yutaka Matsuo

ACS Applied Energy Materials Vol. 6 ( 24 ) page： 12226 - 12236 2023.12

Highly durable graphene-encapsulated platinum-based electrocatalyst for oxygen reduction reactions synthesized by solution plasma process Reviewed

Jae-Hyeok Park, Kyusung Kim, Xiaoyang Wang, Miftakhul Huda, Yasuyuki Sawada, Yutaka Matsuo, Nagahiro Saito, Masaya Kawasumi

Journal of Power Sources Vol. 580 page： 233419 - 233419 2023.10

Evaporable Indano[60]fullerene Ketone for the Electron Transport Layer of Inverted Perovskite Solar Cells Reviewed

Yutaka Matsuo, Soma Ishikawa, Hirofumi Amada, Kento Yokoyama, Qing-jun Shui, Miftakhul Huda, Naoki Ueoka, Hao-Sheng Lin

Chemistry Letters Vol. 52 ( 8 ) page： 685 - 687 2023.8

Cationic Nitrogen-doped Graphene Coated Silver as Low-work Function Electrode for Inverted Perovskite Solar Cells Reviewed

Kento Yokoyama, Hao-Sheng Lin, Qing-Jun Shui, Xiaoyang Wang, Nagahiro Saito, Yutaka Matsuo

Applied Physics Express Vol. 16 ( 8 ) page： 081001 2023.8

Spiro-OMeTAD Versus PTAA for Single-walled Carbon Nanotubes Electrode in Perovskite Solar Cells Reviewed International coauthorship

Bo-Wen Zhang, Hao-Sheng Lin, Yang Qiu, Qing-Jun Shui, Yong-Ji Zheng, Mohamad Almesfer, Esko I. Kauppinen, Yutaka Matsuo, Shigeo Maruyama

Carbon Vol. 205 page： 321 - 327 2023.3

Sequential click modification of a lithium-ion endohedral fullerene connecting small molecules through a dieneazide linker Reviewed

Fujiki Shogo, Takada Takumi, Nagasawa Shota, Okada Hiroshi, Sasano Yusuke, Kwon Eunsang, Matsuo Yutaka, Iwabuchi Yoshiharu

CHEMICAL COMMUNICATIONS Vol. 59 ( 9 ) page： 1237 - 1240 2023.1

A mechanistic study on enhanced PEDOT:PSS for organic solar cells using semiconducting single-walled carbon nanotubes in different diameters Reviewed Open Access

Lin Hao-Sheng, Miyata Daisuke, Yagisawa Mizuki, Huda Miftakhul, Hashimoto Satoru, Hashimoto Takeshi, Matsuo Yutaka

APPLIED PHYSICS EXPRESS Vol. 15 ( 12 ) page： 121001 2022.12

Inkjet Printing of Mechanochromic Fluorenylidene-Acridane Reviewed Open Access

Keisuke Ogumi, Kohki Nagata, Yuki Takimoto, Kentaro Mishiba, Yutaka Matsuo

SCIENTIFIC REPORTS Vol. 12 page： 16997 2022.10

Synthesis of neutral Li-endohedral PCBM: an n-dopant for fullerene derivatives Reviewed International coauthorship

Ueno Hiroshi, Kitabatake Daiki, Lin Hao-Sheng, Ma Yue, Jeon Il, Izawa Seiichiro, Hiramoto Masahiro, Misaizu Fuminori, Maruyama Shigeo, Matsuo Yutaka

CHEMICAL COMMUNICATIONS Vol. 58 ( 73 ) page： 10190 - 10193 2022.9

Synthesis of n-type [60]Fullerene Derivatives with Sterically Bulky tert-Butyl Groups for Vacuum Deposition Processes Reviewed International coauthorship Open Access

Shibuya Hiromasa, Choi Yeong Suk, Choi Taejin, Yun Sungyoung, Moon Juhee, Matsuo Yutaka

CHEMISTRY-AN ASIAN JOURNAL Vol. 17 page： e202200609 2022.9

Quantitative and high-resolution mechanical pressure sensing functions of mechanochromic fluorenylidene-acridane Reviewed Open Access

Ogumi Keisuke, Nagata Kohki, Takimoto Yuki, Mishiba Kentaro, Matsuo Yutaka

JOURNAL OF MATERIALS CHEMISTRY C Vol. 10 ( 31 ) page： 11181 - 11186 2022.8

Triarylamine/Bithiophene Copolymer with Enhanced Quinoidal Character as Hole-Transporting Material for Perovskite Solar Cells Reviewed Open Access

Lin Hao-Sheng, Doba Takahiro, Sato Wataru, Matsuo Yutaka, Shang Rui, Nakamura Eiichi

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION Vol. 61 page： e202203949 2022.5

Scalable eDIPS-based single-walled carbon nanotube films for conductive transparent electrodes in organic solar cells Reviewed

Lin Hao-Sheng, Hatomoto Riku, Miyata Daisuke, Huda Miftakhul, Jeon Il, Hashimoto Satoru, Hashimoto Takeshi, Matsuo Yutaka

APPLIED PHYSICS EXPRESS Vol. 15 ( 4 ) page： 046505 2022.4

Multi-Functional MoO3 Doping of Carbon-Nanotube Top Electrodes for Highly Transparent and Efficient Semi-Transparent Perovskite Solar Cells Reviewed International coauthorship

Seungju Seo, Kosuke Akino, Jeong-Seok Nam, Ahmed Shawky, Hao-Sheng Lin, Hiroki Nagaya, Esko I. Kauppinen, Rong Xiang, Yutaka Matsuo, Il Jeon, Shigeo Maruyama

ADVANCED MATERIALS INTERFACES Vol. 9 page： 2101595 2022.2

Facile Multiple Alkylations of C-60 Fullerene Reviewed Open Access

Miwa Kazuhira, Aoyagi Shinobu, Sasamori Takahiro, Morisako Shogo, Ueno Hiroshi, Matsuo Yutaka, Yorimitsu Hideki

MOLECULES Vol. 27 ( 2 ) page： 450 2022.1

Synthesis of Conjugated Donor-Acceptor Antiaromatic Porphyrins and Their Application to Perovskite Solar Cells Reviewed International coauthorship

Zheng Xue-Lin, Lin Hao-Sheng, Zhang Bo-Wen, Maruyama Shigeo, Matsuo Yutaka

JOURNAL OF ORGANIC CHEMISTRY Vol. 87 page： 5457 - 5463 2021.12

An Adamantane Capsule and its Efficient Uptake of Spherical Guests up to 3 nm in Water Reviewed

Katagiri Yuri, Tsuchida Yamato, Matsuo Yutaka, Yoshizawa Michito

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Vol. 143 page： 21492 - 21496 2021.12

Multi-Walled Carbon Nanotube-Assisted Encapsulation Approach for Stable Perovskite Solar Cells Reviewed International coauthorship Open Access

Jin-Myung Choi, Hiroki Suko, Kyusun Kim, Jiye Han, Sangsu Lee, Yutaka Matsuo, Shigeo Maruyama, Il Jeon, Hirofumi Daiguji

Molecules Vol. 26 ( 16 ) page： 5060 2021.8

Cationic Nitrogen-doped Graphene as p-Type Modifier for High-performance PEDOT:PSS Hole-transporters in Organic Solar Cells Reviewed International coauthorship

Hao-Sheng Lin, Takuhei Kaneko, Soma Ishikawa, Il Jeon, Sangwoo Chae, Takumi Yana, Nagahiro Saito, Yutaka Matsuo

JAPANESE JOURNAL OF APPLIED PHYSICS Vol. 60 ( 7 ) page： 070902 2021.6

One-step Direct Oxidation of Fullerene-fused Alkoxy Ethers to Ketones for Evaporable Fullerene Derivatives Reviewed International coauthorship Open Access

Hao-Sheng Lin, Yue Ma, Rong Xiang, Sergei Manzhos, Il Jeon, Shigeo Maruyama, Yutaka Matsuo

Communications Chemistry Vol. 4 ( 1 ) page： 74 2021.5

Controlled Removal of Surfactants from Double-Walled Carbon Nanotubes for Stronger p-Doping Effect and Its Demonstration in Perovskite Solar Cells Reviewed International coauthorship

Shawky Ahmed, Nam Jeong-Seok, Kim Kyusun, Han Jiye, Yoon Jungjin, Seo Seungju, Lee Chang Soo, Xiang Rong, Matsuo Yutaka, Lee Hyuck Mo, Maruyama Shigeo, Jeon Il

Small Methods Vol. 5 ( 6 ) page： 2100080 2021.4

Synthesis of 5,15-meso-Bis(2-chlorothiophen-3-yl)porphyrin as a Building Block for Further Functional Materials Reviewed International coauthorship

Safi Ullah, Keisuke Ogumi, Xuelin Zhen, Huan Wang, Yutaka Matsuo

Journal of Porphyrins and Phthalocyanines Vol. 25 page： 944 - 950 2021.4

Creation of Highly Efficient and Durable Organic and Perovskite Solar Cells Using Nanocarbon Materials Reviewed Open Access

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN Vol. 94 ( 3 ) page： 1080 - 1089 2021.3

Magnesium Diethynylporphyrin Derivatives with Strong Near-Infrared Absorption for Solution-process Bulk Heterojunction Organic Solar Cells Reviewed Open Access

Keisuke Ogumi, Takafumi Nakagawa, Masahiro Nakano, Yutaka Matsuo

JOURNAL OF PORPHYRINS AND PHTHALOCYANINES Vol. 25 ( 2 ) page： 128 - 134 2021.2

Denatured M13 Bacteriophage-Templated Perovskite Solar Cells Exhibiting High Efficiency Reviewed International coauthorship Open Access

Hao-Sheng Lin, Jong-Min Lee, Jiye Han, Changsoo Lee, Seungju Seo, Shaun Tan, Hyuck Mo Lee, Eun Jung Choi, Michael S. Strano, Yang Yang, Shigeo Maruyama, Il Jeon, Yutaka Matsuo, Jin-Woo Oh

ADVANCED SCIENCE Vol. 7 ( 20 ) page： 2000782 2020.10

Solvation-Free Li+ Lewis Acid Enhancing Reaction: Kinetic Study of [5,6]-Li+@PCBM to [6,6]-Li+@PCBM Reviewed International coauthorship

Yue Ma, Hiroshi Ueno, Hiroshi Okada, Sergei Manzhos, Yutaka Matsuo

Organic Letters Vol. 22 ( 18 ) page： 7239 - 7243 2020.9

Recent Progress in Porphyrin- and Phthalocyanine-containing Perovskite Solar Cells Reviewed Open Access

Yutaka Matsuo, Keisuke Ogumi, Il Jeon, Huan Wang, Takafumi Nakagawa

RSC ADVANCES Vol. 10 ( 54 ) page： 32678 - 32689 2020.9

Equilibrium and Thermodynamic Studies of Chromic Overcrowded Fluorenylidene-Acridanes with Modified Fluorene Moieties Reviewed International coauthorship Open Access

Ya Wang, Yue Ma, Keisuke Ogumi, Bing Wang, Takafumi Nakagawa, Yao Fu, Yutaka Matsuo

Communications Chemistry Vol. 3 ( 1 ) page： 93 2020.7

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC

DOI： 10.1038/s42004-020-00345-6

Other Link： http://www.nature.com/articles/s42004-020-00345-6

MoS2-Carbon Nanotube Heterostructure as Efficient Hole Transporters and Conductors in Perovskite Solar Cells Reviewed International coauthorship

Yang Qian, Seungju Seo, Il Jeon, Haosheng Lin, Shuhei Okawa, Yongjia Zheng, Ahmed Shawky, Anton Anisimov, Esko I. Kauppinen, Jing Kong, Rong Xiang, Yutaka Matsuo, Shigeo Maruyama

APPLIED PHYSICS EXPRESS Vol. 13 ( 7 ) page： 075009 2020.7

Carbon Nanotubes to Outperform Metal Electrodes in Perovskite Solar Cells via Dopant Engineering and Hole-Selectivity Enhancement Reviewed International coauthorship

Il Jeon, Ahmed Shawky, Seungju Seo, Yang Qian, Anton Anisimov, Esko I. Kauppinen, Yutaka Matsuo, Shigeo Maruyama

JOURNAL OF MATERIALS CHEMISTRY A Vol. 8 ( 22 ) page： 11141 - 11147 2020.6

Polyaromatic Nanotweezers on Semiconducting Carbon Nanotubes for the Growth and Interfacing of Lead Halide Perovskite Crystal Grains in Solar Cells Reviewed International coauthorship

Hao-Sheng Lin, Shunhei Okawa, Yue Ma, Satoshi Yotsumoto, Changsoo Lee, Shaun Tan, Sergei Manzhos, Michito Yoshizawa, Shohei Chiashi, Hyuck Mo Lee, Takeshi Tanaka, Hiromichi Kataura, Il Jeon, Yutaka Matsuo, Shigeo Maruyama

CHEMISTRY OF MATERIALS Vol. 32 ( 12 ) page： 5125 - 5133 2020.5

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

Perovskite crystal grain size control, grain boundary passivation, and grain bridging are the keys to obtaining high efficiency in perovskite solar cells. A small amount of semi-conducting single-walled carbon nanotubes added to a perovskite active layer can achieve this. In particular, the surfactants attached to the semiconducting single-walled carbon nanotubes a crucial role. In this work, we synthesized a new surfactant, 4,6-di(anthracen-9-yl)-1,3-phenylene bis(dimethylcarbamate), which has a polyaromatic group on one end and a urea-analogue carbamate group on the other end. The polyaromatic anthracene end functions as a nanotweezer clenching the carbon nanotubes strongly via pi-pi interaction while the carbamate end interacts with Pb2+, functioning as a strong Lewis base. In addition, the new surfactant has conjugated double bonds with a suitable bandgap, resulting in enhanced charge mobility in the perovskite film. Overall, the new surfactant-clenched semiconducting carbon nanotubes showcase superior effectiveness as passivators and charge bridges in perovskite solar cells as compared to the conventional deoxycholate surfactant-wrapped semiconducting single-walled carbon nanotubes. The new surfactant-attached semiconducting carbon nanotube-added NH3CH3PbI3-based perovskite solar cells exhibited a power conversion efficiency of 20.7%, which is higher than that of the reference devices with no additives (18.4%) and the previously reported semiconducting single-walled carbon nanotube-added devices (19.7% in this work and 19.5% in the literature).

DOI： 10.1021/acs.chemmater.0c01011

Chemical reduction of Li+@C60 by decamethylferrocene to produce neutral Li+@C60•– Reviewed

Nickel-Catalyzed Deaminative Acylation of Activated Aliphatic Amines with Aromatic Amides via C-N Bond Activation Reviewed International coauthorship Open Access

Chu-guo Yu, Yutaka Matsuo

ORGANIC LETTERS Vol. 22 ( 3 ) page： 950 - 955 2020.2

Multifunctional Effect of p‐Doping, Antireflection, and Encapsulation by Polymeric Acid for High Efficiency and Stable Carbon Nanotube‐Based Silicon Solar Cells Reviewed International coauthorship

Adv. Energy Mater. Vol. 10 page： 1902389 2020.1

Highly Selective Synthesis of Tetrahydronaphthaleno[60]fullerenes via Fullerene-Cation-Mediated Intramolecular Cyclization Reviewed Open Access

Yang Xiao-Yu, Lin Hao-Sheng, Matsuo Yutaka

JOURNAL OF ORGANIC CHEMISTRY Vol. 84 ( 24 ) page： 16314 - 16322 2019.12

Investigation of charge interaction between fullerene derivatives and single‐walled carbon nanotubes Reviewed International coauthorship Open Access

InfoMat Vol. 1 ( 4 ) page： 559 - 570 2019.12

Hiroshi Okada, Hiroshi Ueno, Yasuhiro Takabayashi, Takeshi Nakagawa, Martina Vrankić, John Arvanitidis, Tetsuro Kusamoto, Kosmas Prassides, Yutaka Matsuo

Carbon Vol. 153 page： 467 - 471 2019.11

Controlled Redox of Lithium-Ion Endohedral Fullerene for Efficient and Stable Metal Electrode-Free Perovskite Solar Cells Reviewed Open Access

Journal of the American Chemical Society Vol. 141 ( 42 ) page： 16553 - 16558 2019.10

Highly Selective and Scalable Fullerene-Cation-Mediated Synthesis Accessing Cyclo[60]fullerenes with Five-Membered Carbon Ring and Their Application to Perovskite Solar Cells Reviewed Open Access

Hao-Sheng Lin, Il Jeon, Yingqian Chen, Xiao-Yu Yang, Takafumi Nakagawa, Shigeo Maruyama, Sergei Manzhos, Yutaka Matsuo

Chemistry of Materials Vol. 31 ( 20 ) page： 8432 - 8439 2019.10

High-yielding Pd-2(dba)(3)center dot C6H6-based four-fold Sonogashira coupling with selenophene-conjugated magnesium tetraethynylporphyrin for organic solar cells Reviewed International coauthorship Open Access

RSC ADVANCES Vol. 9 ( 56 ) page： 32562 - 32572 2019.10

Li@C-60 endohedral fullerene as a supraatomic dopant for C-60 electron-transporting layers promoting the efficiency of perovskite solar cells Reviewed International coauthorship

Ueno Hiroshi, Jeon Il, Lin Hao-sheng, Thote Abhishek, Nakagawa Takafumi, Okada Hiroshi, Izawa Seiichiro, Hiramoto Masahiro, Daiguji Hirofumi, Maruyama Shigeo, Matsuo Yutaka

CHEMICAL COMMUNICATIONS Vol. 55 ( 79 ) page： 11837 - 11839 2019.10

Prediction of magnesium tetraethynylporphyrin’s solubility by theoretical calculation Reviewed Open Access

Journal of Porphyrins and Phthalocyanines Vol. 23 ( 10 ) page： 1144 - 1148 2019.10

Language：English

<jats:p> To investigate the solubility of porphyrin derivatives, their intermolecular interaction energies were calculated by the counterpoise method at the B97D3/6-31G(d) level. It was found that the calculated intermolecular interaction energies corresponded to the solubility measured by UV-vis spectroscopy. This correlation was consistent with differences in substituents and in the metals in the porphyrin core. </jats:p>

DOI： 10.1142/S1088424619501475

Synergic Catalysts of Polyoxometalate@Cationic Porous Aromatic Frameworks: Reciprocal Modulation of Both Capture and Conversion Materials Reviewed

Song Jian, Li Yue, Cao Ping, Jing Xiaofei, Faheem Muhammad, Matsuo Yutaka, Zhu Youliang, Tian Yuyang, Wang Xiaohong, Zhu Guangshan

ADVANCED MATERIALS Vol. 31 ( 40 ) 2019.10

Dialkoxymethano[60]fullerenes as electron acceptors in thin-film organic solar cells Reviewed

Tetrahedron Vol. 75 ( 38 ) 2019.9

Improved solubility of asymmetric tetraethynylporphyrin derivatives for solution-processed organic solar cells Reviewed

Keisuke Ogumi, Takafumi Nakagawa, Hiroshi Okada, Yutaka Matsuo

Organic Electronics Vol. 71 page： 50 - 57 2019.8

High-Performance Solution-Processed Double-Walled Carbon Nanotube Transparent Electrode for Perovskite Solar Cells Reviewed International coauthorship

Il Jeon, Jungjin Yoon, Unsoo Kim, Changsoo Lee, Rong Xiang, Ahmed Shawky, Jun Xi, Junseop Byeon, Hyuck Mo Lee, Mansoo Choi, Shigeo Maruyama, Yutaka Matsuo

Advanced Energy Materials Vol. 9 ( 27 ) 2019.7

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Double-walled carbon nanotubes are between single-walled carbon nanotubes and multiwalled carbon nanotubes. They are comparable to single-walled carbon nanotubes with respect to the light optical density, but their mechanical stability and solubility are higher. Exploiting such advantages, solution-processed transparent electrodes are demonstrated using double-walled carbon nanotubes and their application to perovskite solar cells is also demonstrated. Perovskite solar cells which harvest clean solar power have attracted a lot of attention as a next-generation renewable energy source. However, their eco-friendliness, cost, and flexibility are limited by the use of transparent oxide conductors, which are inflexible, difficult to fabricate, and made up of expensive rare metals. Solution-processed double-walled carbon nanotubes can replace conventional transparent electrodes to resolve such issues. Perovskite solar cells using the double-walled carbon nanotube transparent electrodes produce an operating power conversion efficiency of 17.2% without hysteresis. As the first solution-processed electrode-based perovskite solar cells, this work will pave the pathway to the large-size, low-cost, and eco-friendly solar devices.

DOI： 10.1002/aenm.201901204

Mechanochromism, Twisted/Folded Structure Determination, and Derivatization of (N -Phenylfluorenylidene)acridane Reviewed

Yutaka Matsuo, Ya Wang, Hiroshi Ueno, Takafumi Nakagawa, Hiroshi Okada

Angewandte Chemie International Edition Vol. 58 ( 26 ) page： 8762 - 8767 2019.6

Semiconducting carbon nanotubes as crystal growth templates and grain bridges in perovskite solar cells

Seo Seungju, Jeon Il, Xiang Rong, Lee Changsoo, Zhang Hao, Tanaka Takeshi, Lee Jin-Wook, Suh Donguk, Ogamoto Tatsuro, Nishikubo Ryosuke, Saeki Akinori, Chiashi Shohei, Shiomi Junichiro, Kataura Hiromichi, Lee Hyuck Mo, Yang Yang, Matsuo Yutaka, Maruyama Shigeo

JOURNAL OF MATERIALS CHEMISTRY A Vol. 7 ( 21 ) page： 12987 - 12992 2019.6

Single-Walled Carbon Nanotubes in Emerging Solar Cells: Synthesis and Electrode Applications Reviewed

Jeon Il, Xiang Rong, Shawky Ahmed, Matsuo Yutaka, Maruyama Shigeo

ADVANCED ENERGY MATERIALS Vol. 9 ( 23 ) 2019.6

Highly soluble C2v-symmetrical fullerene derivatives: efficient synthesis, characterization, and electrochemical study Reviewed

Yue Ma, Kouya Uchiyama, Hiroshi Ueno, Hiroshi Okada, Hiroshi Moriyama, Yutaka Matsuo

Organic Chemistry Frontiers Vol. 6 ( 9 ) page： 1372 - 1377 2019.5

Synthesis of Benzothieno[60]fullerenes Through Fullerenyl Cation Intermediates Reviewed International coauthorship

Yutaka Matsuo, Yun Yu, Xiao-Yu Yang, Hiroshi Ueno, Hiroshi Okada, Hiromasa Shibuya, Yeong Suk Choi, Yong Wan Jin

Journal of Organic Chemistry Vol. 84 page： 6270 - 6277 2019.4

Effects of optical interference and optimized crystallinity in organic photovoltaic cells with a low-bandgap small molecule fabricated by dry process Reviewed

Yamamoto Kohei, Miyadera Tetsuhiko, Matsuo Yutaka, Kuwabara Takayuki, Takahashi Kohshin, Taima Tetsuya, Chikamatsu Masayuki

JAPANESE JOURNAL OF APPLIED PHYSICS Vol. 58 2019.4

Stable and Reproducible 2D/3D Formamidinium–Lead–Iodide Perovskite Solar Cells Reviewed International coauthorship

Abhishek Thote, Il Jeon, Jin-Wook Lee, Seungju Seo, Hao-Sheng Lin, Yang Yang, Hirofumi Daiguji, Shigeo Maruyama, Yutaka Matsuo

ACS Applied Energy Materials Vol. 2 page： 2486 - 2493 2019.3

Fluorescein-based fluorescent porous aromatic framework for Fe3+ detection with high sensitivity Reviewed

Tingting Ma, Xue Zhao, Yutaka Matsuo, Jian Song, Rui Zhao, Muhammad Faheem, Mo Chen, Yunfeng Zhang, Yuyang Tian, Guangshan Zhu

Journal of Materials Chemistry C Vol. 7 ( 8 ) page： 2327 - 2332 2019.2

Star-shaped magnesium tetraethynylporphyrin bearing four peripheral electron-accepting diketopyrrolopyrrole functionalities for organic solar cells Reviewed

Wang Huan, Yue Qihui, Nakagawa Takafumi, Zieleniewska Anna, Okada Hiroshi, Ogumi Keisuke, Ueno Hiroshi, Guldi Dirk M., Zhu Xiaozhang, Matsuo Yutaka

JOURNAL OF MATERIALS CHEMISTRY A Vol. 7 ( 8 ) page： 4072 - 4083 2019.2

Reduced Knoevenagel Reaction of Acetetracenylene-1,2-dione with Acceptor Units for Luminescent Tetracene Derivatives Reviewed International coauthorship

Yutaka Matsuo, Chu-Guo Yu, Takafumi Nakagawa, Hiroshi Okada, Hiroshi Ueno, Tian-Ge Sun, Yu-Wu Zhong

The Journal of Organic Chemistry Vol. 84 ( 4 ) page： 2339 - 2345 2019.2

Polarity engineering of porous aromatic frameworks for specific water contaminant capture Reviewed

Xiaoshan Shen, Muhammad Faheem, Yutaka Matsuo, Saba Aziz, Xu Zhang, Yuhan Li, Jian Song, Yuyang Tian, Guangshan Zhu

Journal of Materials Chemistry A Vol. 7 ( 6 ) page： 2507 - 2512 2019.2

Formation of Environmentally Stable Hole-doped Graphene Films with Instantaneous and High-density Carrier Doping via a Boron-based Oxidant Reviewed Open Access

Kaito Kanahashi, Naoki Tanaka, Yoshiaki Shoji, Mina Maruyama, Il Jeon, Kenji Kawahara, Masatou Ishihara, Masataka Hasegawa, Hiromichi Ohta, Hiroki Ago, Yutaka Matsuo, Susumu Okada, Takanori Fukushima, Taishi Takenobu

NPJ 2D MATERIALS AND APPLICATIONS Vol. 3 ( 1 ) page： 7 2019.2

High-Working-Pressure Sputtering of ZnO for Stable and Efficient Perovskite Solar Cells Reviewed International coauthorship

Abhishek Thote, Il Jeon, Hao-Sheng Lin, Sergei Manzhos, Takafumi Nakagawa, Donguk Suh, Junho Hwang, Makoto Kashiwagi, Junichiro Shiomi, Shigeo Maruyama, Hirofumi Daiguji, Yutaka Matsuo

ACS Applied Electronic Materials Vol. 1 page： 389 - 396 2019.2

Vapor-Assisted Ex-Situ Doping of Carbon Nanotube toward Efficient and Stable Perovskite Solar Cells Reviewed International coauthorship

Jin-Wook Lee, Il Jeon, Hao-Sheng Lin, Seungju Seo, Tae-Hee Han, Anton Anisimov, Esko I. Kauppinen, Yutaka Matsuo, Shigeo Maruyama, Yang Yang

Nano Letters Vol. 19 page： 2223 - 2230 2019.1

Investigation for Energy Levels of an Organic Thin-film Semiconductor by Photoemission Yield Spectroscopy in Air Reviewed

Ogumi Keisuke, Fujimaki Yasuto, Nakagawa Takafumi, Matsuo Yutaka

BUNSEKI KAGAKU Vol. 67 ( 11 ) page： 647 - 651 2018.11

Magnesium Tetra(phenylethynyl)porphyrin: Stepwise Synthetic Route, Crystal Structures, and Longer Singlet Excited-State Lifetime than Zinc Congener Reviewed

Takafumi Nakagawa, Huan Wang, Anna Zieleniewska, Hiroshi Okada, Shinobu Aoyagi, Dirk M. Guldi, Yutaka Matsuo

Chemistry - An Asian Journal Vol. 13 ( 20 ) page： 3032 - 3039 2018.10

Functionalization of [60]fullerene through fullerene cation intermediates Reviewed

Hao-Sheng Lin, Yutaka Matsuo

Chemical Communications Vol. 54 ( 80 ) page： 11244 - 11259 2018.10

Achieving High Efficiency in Solution-Processed Perovskite Solar Cells Using C60/C70 Mixed Fullerenes Reviewed International coauthorship

Lin H.-S, Jeon I, Xiang R, Seo S, Lee J.-W, Li C, Pal A, Manzhos S, Goorsky M.S, Yang Y, Maruyama S, Matsuo Y

ACS Applied Materials and Interfaces Vol. 10 ( 46 ) page： 39590 - 39598 2018.9

Octaalkoxyfullerenes: Widely LUMO-Tunable C2v-Symmetric Fullerene Derivatives Reviewed

Hiroshi Ueno, Kouya Uchiyama, Yue Ma, Keita Watanabe, Kenji Yoza, Yutaka Matsuo, Hiroshi Moriyama

The Journal of Organic Chemistry Vol. 83 ( 17 ) page： 10655 - 10659 2018.9

Enhanced Electrical Conduction in Anatase TaON via Soft Chemical Lithium Insertion toward Electronics Application Reviewed

Atsushi Suzuki, Yasushi Hirose, Takafumi Nakagawa, Satoshi Fujiwara, Shoichiro Nakao, Yutaka Matsuo, Isao Harayama, Daiichiro Sekiba, Tetsuya Hasegawa

ACS Applied Nano Materials Vol. 1 ( 8 ) page： 3981 - 3985 2018.8

Electronic structure and cohesive energy of silylmethyl fullerene and methanoindene fullerene solids Reviewed Open Access

Furutani Sho, Matsuo Yutaka, Okada Susumu

Japanese Journal of Applied Physics Vol. 57 ( 8 ) 2018.8

Structure of [60]fullerene with a mobile lithium cation inside Reviewed Open Access

Aoyagi Shinobu, Miwa Kazuhira, Ueno Hiroshi, Okada Hiroshi, Matsuo Yutaka, Kokubo Ken

ROYAL SOCIETY OPEN SCIENCE Vol. 5 ( 7 ) 2018.7

Polymeric Acid-doped Transparent Carbon Nanotube Electrodes for Organic Solar Cells with the Longest Doping Durability Reviewed International coauthorship

Il Jeon, Clement Delacou, Hiroshi Okada, Graham E. Morse, Tae-Hee Han, Yuta Sato, Anton Anisimov, Kazu Suenaga, Esko I. Kauppinen, Shigeo Maruyama, Yutaka Matsuo

Journal of Materials Chemistry A Vol. 6 ( 30 ) page： 14553 - 14559 2018.6

Fullerene-Cation-Mediated Noble-Metal-Free Direct Introduction of Functionalized Aryl Groups onto [60]Fullerene Reviewed

Xiao-Yu Yang, Hao-Sheng Lin, Il Jeon, Yutaka Matsuo

Organic Letters Vol. 20 ( 11 ) page： 3372 - 3376 2018.6

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

Aryl[60]fullerenyl cations (ArC60 +), which were generated by heating aryl[60]fullerenyl dimers (ArC60-C60Ar) to generate aryl[60]fullerenyl radicals (ArC60 •) followed by oxidation using Cu(II) salts (Cu(BF4)2(aq)), were reacted with various functionalized aryl boronic acids to produce functionalized 1,4-diaryl[60]fullerenes. This protocol tolerated various functional groups, such as OH, NH2, COCH3, and Cl substituents, with yields reaching 93%. C60Ar1Ar2 (Ar2 = p-NH2C6H4) was used as a dopant in a photoactive CH3NH3PbI3 layer of a perovskite solar cell.

DOI： 10.1021/acs.orglett.8b01295

Lithium-Ion Endohedral Fullerene (Li+@C-60) Dopants in Stable Perovskite Solar Cells Induce Instant Doping and Anti-Oxidation

Jeon Il, Ueno Hiroshi, Seo Seungju, Aitola Kerttu, Nishikubo Ryosuke, Saeki Akinori, Okada Hiroshi, Boschloo Gerrit, Maruyama Shigeo, Matsuo Yutaka

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION Vol. 57 ( 17 ) page： 4607 - 4611 2018.4

Engineering High-performance and Air-stable PBTZT-stat-BDTT-8:PC61BM/PC71BM Organic Solar Cells Reviewed International coauthorship

Il Jeon, Ryohei Sakai, Seungju Seo, Graham E. Morse, Hiroshi Ueno, Takafumi Nakagawa, Yang Qian, Shigeo Maruyama, Yutaka Matsuo

Journal of Materials Chemistry A Vol. 6 ( 14 ) page： 5746 - 5751 2018.4

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Royal Society of Chemistry

High-performance air-stable PBTZT-stat-BDTT-8 organic solar cells were fabricated using mixed C60/C70 fullerene acceptors. Normal-architecture devices using PBTZT-stat-BDTT-8 with PC71BM produced a power conversion efficiency (PCE) of 9.38%. An inverted-architecture, which possesses higher stability, was fabricated using a more economical PC61BM and PC71BM mixture with solution-processed PEDOT:PSS on top and produced a PCE of 8.15%. Exploiting the viscous nature of PBTZT-stat-BDTT-8, the slow evaporation effect was utilised to achieve an even higher efficiency of 8.73%. A stability test was conducted under operating conditions and our devices showed remarkably higher stability compared with PTB7-based devices.

DOI： 10.1039/c7ta11095b

Anthracene-Based Organic Small-Molecule Electron-Injecting Material for Inverted Organic Light-Emitting Diodes Reviewed

Yutaka Matsuo, Hiroshi Okada, Yasuhiro Kondo, Il Jeon, Huan Wang, Yun Yu, Takeshi Matsushita, Motoki Yanai, Toshiaki Ikuta

ACS Applied Materials and Interfaces Vol. 10 ( 14 ) page： 11810 - 11817 2018.4

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

A diphenylanthracene dimethylamine derivative (9-{3,5-di(N,N-dimethylaminoethoxy)phenyl}-10-phenyl-anthracene, DPAMA) was synthesized by the Suzuki-Miyaura cross-coupling reaction. Its ammonium salt, 9-{3,5-di(trimethylammonium ethoxy)phenyl}-10-phenyl-anthracene dichloride (DPAMA-Cl), was also synthesized as a reference material. DPAMA was characterized by UV-vis and fluorescence spectroscopy, cyclic voltammetry, photoelectron yield spectroscopy, and X-ray photoelectron spectroscopy to evaluate the work function-modifying ability of DPAMA on indium tin oxide (ITO) and ZnO. The work functions of ITO and ZnO changed from 4.4 and 4.0 eV (pristine) to 3.8 and 3.9 eV, respectively. Using this surface modification effect of DPAMA, inverted organic light-emitting diodes were fabricated with device structures of ITO/DPAMA/Alq3/NPD/MoO3/Al (Alq3 = tris(8-hydroxyquinolinato)aluminum
NPD = N,N′-di-[(1-naphthyl)-N,N′-diphenyl]-1,1′-(biphenyl)-4,4′-diamine) and ITO/ZnO/DPAMA/Alq3/NPD/MoO3/Al. Both devices showed good performance at the range of current density, 1-300 mA/cm2. The best inverted organic light-emitting diodes device showed luminance of 7720 cd/m2, current efficiency of 4.51 cd/A, and external quantum efficiency of 1.45%. Also, poly(3-hexylthiophene):mixed phenyl-C61 and C71 butyric acid methyl ester-based organic solar cells using DPAMA and DPAMA-Cl as electron-transporting materials showed power conversion efficiencies of 3.3 and 3.4%, respectively.

DOI： 10.1021/acsami.8b00603

Lithium-Ion Endohedral Fullerene (Li+@C60) Dopants in Stable Perovskite Solar Cells Induce Instant Doping and Anti-Oxidation Reviewed International coauthorship

Il Jeon, Hiroshi Ueno, Seungju Seo, Kerttu Aitola, Ryosuke Nishikubo, Akinori Saeki, Hiroshi Okada, Gerrit Boschloo, Shigeo Maruyama, Yutaka Matsuo

Angewandte Chemie International Edition Vol. 130 ( 17 ) page： 4697 2018.3

Carbon-sandwiched perovskite solar cell Reviewed

Namyoung Ahn, Il Jeon, Jungjin Yoon, Esko I. Kauppinen, Yutaka Matsuo, Shigeo Maruyama, Mansoo Choi

Journal of Materials Chemistry A Vol. 6 ( 4 ) page： 1382 - 1389 2018.1

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

Promising perovskite solar cell technology with soaring power conversion efficiencies has the common problems of low stability and high cost. This work provides a solution to these problems by employing a carbon sandwich structure, in which the fullerene bottom layer solves the stability issue and the carbon nanotube top electrode layer offers the merits of having high stability and being low-cost. Devices fabricated using different hole-transporting materials infiltrated into carbon nanotube networks were examined for their performance and stability under constant illumination in air. Polymeric hole-transporting layers show much higher stability when combined with carbon nanotubes due to their compact nature and stronger interaction with the carbon network. As a result, the encapsulated device showed high stability both in air and under light illumination, maintaining up to 80% of the initial efficiency after 2200 hours under actual operation conditions. Cost analysis also shows that using the polymeric hole-transporting materials in carbon nanotube films brings the fabrication cost down to less than 5.5% that of conventional devices. Our study proposes a promising cell structure toward highly stable and low-cost perovskite photovoltaic technologies for the future.

DOI： 10.1039/c7ta09174e

A Helically-Twisted Ladder Based on 9,9'-Bifluorenylidene: Synthesis, Characterization, and Charge Transport Properties Reviewed

Jinjia Xu, Atsuro Takai, Alisa Bannaron, Takafumi Nakagawa, Yutaka Matsuo, Manabu Sugimoto, Yoshitaka Matsushita, Masayuki Takeuchi

Materials Chemistry Frontiers Vol. 2 page： 780 - 784 2018.1

A fluorenylidene-acridane that becomes dark in color upon grinding-ground state mechanochromism by conformational change Reviewed Open Access

Tsuyoshi Suzuki, Hiroshi Okada, Takafumi Nakagawa, Kazuki Komatsu, Chikako Fujimoto, Hiroyuki Kagi, Yutaka Matsuo

Chemical Science Vol. 9 ( 2 ) page： 475 - 482 2018.1

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

We report mechanochromic color change controlled by conformational change (between folded and twisted conformers) of fluorenylidene-acridanes (FAs). FAs with four N-alkyl groups (methyl, ethyl, n-butyl and n-octyl) were synthesized via the Barton-Kellogg reaction of diazofluorene and electrophilic N-tert-butoxy carbonyl thioacridone, deprotection of the tert-butoxy carbonyl group gives fluorenylacridine, and alkylation on the nitrogen atom is done using alkyl tosylate or triflate. FAs were characterized by NMR, UV-vis absorption and photoluminescence spectroscopy, theoretical calculation, cyclic voltammetry, and powder and single-crystal X-ray analyses. The color and folded/twisted conformation of the FAs were changed by the choice of substituent on the nitrogen atom, physical state (solution or solid), and morphology (crystalline or amorphous). Grinding of N-methyl FA solids, using an agate mortar, caused the morphology to change from a crystalline to amorphous state, which induced a conformational change from the folded to the twisted conformer, and a mechanochromic color change from yellow to dark green. The reverse color change, along with a morphological and conformational change to the folded conformer, was performed by solvent vapor exposure (chloroform). The twisted and folded conformers showed ambipolar (hole/electron) and hole-only transport properties, respectively.

DOI： 10.1039/c7sc03567e

Non-doped and unsorted single-walled carbon nanotubes as carrier-selective, transparent, and conductive electrode for perovskite solar cells Reviewed International coauthorship

Takahiro Sakaguchi, Il Jeon, Takaaki Chiba, Ahmed Shawky, Rong Xiang, Shohei Chiashi, Esko I. Kauppinen, Nam-Gyu Park, Yutaka Matsuo, Shigeo Maruyama

MRS Communications Vol. 8 ( 3 ) page： 1058 - 1063 2018

Substituent effects in magnesium tetraethynylporphyrin with two diketopyrrolopyrrole units for bulk heterojunction organic solar cells Reviewed

Ogumi Keisuke, Nakagawa Takafumi, Okada Hiroshi, Sakai Ryohei, Wang Huan, Matsuo Yutaka

JOURNAL OF MATERIALS CHEMISTRY A Vol. 5 ( 44 ) page： 23067 - 23077 2017.11

Comparative density functional theory-density functional tight binding study of fullerene derivatives: effects due to fullerene size, addends, and crystallinity on band structure, charge transport and optical properties Reviewed

Amrita Pal, Lai Kai Wen, Chia Yao Jun, Il Jeon, Yutaka Matsuo, Sergei Manzhos

PHYSICAL CHEMISTRY CHEMICAL PHYSICS Vol. 19 ( 41 ) page： 28330 - 28343 2017.11

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

We present a systematic comparative density functional theory-density functional tight binding study of multiple derivatives of C60 and C70 with different addends, in molecular as well as solid state. In particular, effects due to fullerene size, type and number of addends, and of crystallinity on band structure, charge transport, and optical properties are investigated. These are important, in particular, for rational selection of fullerene derivatives as acceptor and electron transport layers in organic as well as planar inverted perovskite solar cells. We find that by the choice of type and number of addends, one can modulate the LUMO within 0.4 eV. Changes in the HOMO can reach 0.7 eV. Substituting C70 for C60 results in destabilization of the HOMO by about 0.1 eV for indene and quinodimethane addends and by a less significant amount for PCBM addends. The effect of C70-C60 substitution on the LUMO is of similar magnitude. A more significant change in HOMO-LUMO energy is seen for the aryl addends. On the other hand, all C70 based molecules have strong visible absorption. For most addends, the crystal packing leads to a stabilization of both the LUMO and HOMO by about similar to 0.2 and similar to 0.1 eV, respectively, vs. single molecules. When using bis-addends, it is also possible to enhance the visible absorption. Electron and hole transport rates are computed to vary vastly depending on the addends chosen; specifically, we compute that indene and quimodimethane addends can enhance charge transport rates while the aryl addend is predicted to result in substantially smaller mobilities of electrons and holes, vs. PC60BM. Furthermore, the -CH2 and bisaddend addition can significantly enhance the charge transfer rates for the PCBM addend.

DOI： 10.1039/c7cp05290a

Carbon Nanotubes versus Graphene as Flexible Transparent Electrodes in Inverted Perovskite Solar Cells Reviewed International coauthorship

Il Jeon, Jungjin Yoon, Namyoung Ahn, Mohamed Atwa, Clement Delacou, Anton Anisimov, Esko I. Kauppinen, Mansoo Choi, Shigeo Maruyama, Yutaka Matsuo

Journal of Physical Chemistry Letters Vol. 8 ( 21 ) page： 5395 - 5401 2017.11

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Transparent carbon electrodes, carbon nanotubes, and graphene were used as the bottom electrode in flexible inverted perovskite solar cells. Their photovoltaic performance and mechanical resilience were compared and analyzed using various techniques. Whereas a conventional inverted perovskite solar cells using indium tin oxide showed a power conversion efficiency of 17.8%, the carbon nanotube- and graphene-based cells showed efficiencies of 12.8% and 14.2%, respectively. An established MoO3 doping was used for carbon electrode-based devices. The difference in the photovoltaic performance between the carbon nanotube- and graphene-based cells was due to the difference in morphology and transmittance. Raman spectroscopy, and cyclic flexural testing revealed that the graphene-based cells were more susceptible to strain than the carbon nanotube-based cells, though the difference was marginal. Overall, despite higher performance, the transfer step for graphene has lower reproducibility. Thus, the development of better graphene transfer methods would help maximize the current capacity of graphene-based cells.

DOI： 10.1021/acs.jpclett.7b02229

PubMed

Perovskite Solar Cells Using Carbon Nanotubes Both as Cathode and as Anode Reviewed International coauthorship

Il Jeon, Seungju Seo, Yuta Sato, Clement Delacou, Anton Anisimov, Kazu Suenaga, Esko I. Kauppinen, Shigeo Maruyama, Yutaka Matsuo

JOURNAL OF PHYSICAL CHEMISTRY C Vol. 121 ( 46 ) page： 25743 - 25749 2017.11

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Organic-inorganic halide perovskite solar cells have received much attention because they achieve high power conversion efficiencies while providing the advantages of thin-film solar cells, namely, solution processability and potentially low fabrication costs. However, at the current level of halide perovskite solar cell technology, these advantages cannot be maximized because of structural and material limitations. Here, we provide a solution to these problems by replacing conventional metal and metal oxide electrodes with carbon nanotube electrodes. We also simplified the structure to achieve entirely solution-processable perovskite solar cells. Through this study, we demonstrate the function of carbon nanotubes as both the anode and the cathode in perovskite solar cells. Economic modeling suggests that this novel architecture reduces costs dramatically. This work realizes innovations in the materials, costs, and processing of inverted-type perovskite solar cells.

DOI： 10.1021/acs.jpcc.7b10334

Synthesis and Crystal Structure of Li+@Fluoreno[60]fullerene: Effect of Encapsulated Lithium Ion on Electrochemistry of Spiroannelated Fullerene Reviewed International coauthorship

Hiroshi Ueno, Hiroshi Okada, Shinobu Aoyagi, Yutaka Matsuo

Journal of Organic Chemistry Vol. 82 page： 11631 - 11635 2017.10

Highly Conductive and Transparent Large-Area Bilayer Graphene Realized by MoCl5 Intercalation Reviewed

Hiroki Kinoshita, Il Jeon, Mina Maruyama, Kenji Kawahara, Yuri Terao, Dong Ding, Rika Matsumoto, Yutaka Matsuo, Susumu Okada, Hiroki Ago

Advanced Materials Vol. 29 ( 41 ) page： 1702141 2017.9

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Bilayer graphene (BLG) comprises a 2D nanospace sandwiched by two parallel graphene sheets that can be used to intercalate molecules or ions for attaining novel functionalities. However, intercalation is mostly demonstrated with small, exfoliated graphene flakes. This study demonstrates intercalation of molybdenum chloride (MoCl5 ) into a large-area, uniform BLG sheet, which is grown by chemical vapor deposition (CVD). This study reveals that the degree of MoCl5 intercalation strongly depends on the stacking order of the graphene; twist-stacked graphene shows a much higher degree of intercalation than AB-stacked. Density functional theory calculations suggest that weak interlayer coupling in the twist-stacked graphene contributes to the effective intercalation. By selectively synthesizing twist-rich BLG films through control of the CVD conditions, low sheet resistance (83 Ω ▫(-1) ) is realized after MoCl5 intercalation, while maintaining high optical transmittance (≈95%). The low sheet resistance state is relatively stable in air for more than three months. Furthermore, the intercalated BLG film is applied to organic solar cells, realizing a high power conversion efficiency.

DOI： 10.1002/adma.201702141

Regiocontrolled Electrosynthesis of [60]Fullerene Bisadducts: Photovoltaic Performance and Crystal Structures of C-60 o-Quinodimethane Bisadducts Reviewed International coauthorship

Zong-Jun Li, Sisi Wang, Shu-Hui Li, Tao Sun, Wei-Wei Yang, Kazutaka Shoyama, Takafumi Nakagawa, Il Jeon, Xiaoniu Yang, Yutaka Matsuo, Xiang Gao

JOURNAL OF ORGANIC CHEMISTRY Vol. 82 ( 16 ) page： 8676 - 8685 2017.8

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

C-60 o-quinodimethane bisadducts [C-60(QM)(2)] are promising electron acceptors for bulk heterojuction (BHJ) organic solar cells (OSCs). However, previous production of C-60(QM)(2) often resulted in excessive regioisomers, which were difficult to purify and might consequently obscure the structure performance study of the organofullerene acceptors. Herein, the electrosynthesis of C-60(QM)(2) is reported. The reaction exhibits a strong regiocontrol with generation of fewer regioisomers. Pure regioisomers of cis-2, trans-3, and e C-60(QM)(2) are obtained, and the structures are solved with single-crystal X-ray diffraction. Interestingly, the cis-2 and trans-3 regioisomers exhibit better photovoltaic performance than the e regioisomer in the OSCs based on poly(3-hexylthiophene) (P3HT), which can be correlated with their structural difference.

DOI： 10.1021/acs.joc.7b01732

PubMed

Crystallographic Structure Determination of Both [5,6]- and [6,6] Isomers of Lithium-Ion-Containing Diphenylmethano[60]fullerene Reviewed

Hiroshi Okada, Hiroki Kawakami, Shinobu Aoyagi, Yutaka Matsuo

JOURNAL OF ORGANIC CHEMISTRY Vol. 82 ( 11 ) page： 5868 - 5872 2017.6

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

Organic functionalization of lithium-ion-containing [60]fullerene, Li+@C-60, was performed by using diphenyl(diazo)methane as a stable, readily available diazo compound to obtain lithium-ion-containing [5,6]- and [6,6]-diphenylmethano[60]fullerenes, Li+@C61Ph2. The bis(trifluoromethanesulfonyl)imide (TFSI) salts of [5,6]- and [6,6]-Li+@C61Ph2 were successfully separated by using a cation exchange column with eluent containing LiTFSI. Improved separation protocol and high crystallinity of ionic components in less polar solvents enabled separate crystallization of each isomer. Both [5,6]-open and [6,6]-closed structures of Li+@C61Ph2 were determined by synchrotron radiation X-ray crystallography. Elucidating the [5,6] -open methano[60]fullerene (fulleroid) structure will contribute to materials research on fulleroids.

DOI： 10.1021/acs.joc.7b00730

Scalable and Solid-state Redox Functionalization of Transparent Single-walled Carbon Nanotube Films for Highly Efficient and Stable Solar Cells Reviewed International coauthorship

Kehang Cui, Yang Qian, Il Jeon, Anton Anisimov, Yutaka Matsuo, Esko I. Kauppinen, Shigeo Maruyama

Advanced Energy Materials Vol. 7 page： 1700449 2017.5

Dual Interfacial Modifications Enable High Performance Semitransparent Perovskite Solar Cells with Large Open Circuit Voltage and Fill Factor Reviewed

Qifan Xue, Yang Bai, Meiyue Liu, Ruoxi Xia, Zhicheng Hu, Ziming Chen, Xiao-Fang Jiang, Fei Huang, Shihe Yang, Yutaka Matsuo, Hin-Lap Yip, Yong Cao

ADVANCED ENERGY MATERIALS Vol. 7 ( 9 ) 2017.5

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

In this work, both anode and cathode interfaces of p-i-n CH3NH3PbI3 perovskite solar cells (PVSCs) are simultaneously modified to achieve large open-circuit voltage (V-oc) and fill factor (FF) for high performance semitransparent PVSCs (ST-PVSCs). At the anode, modified NiO serves as an efficient hole transport layer with appropriate surface property to promote the formation of smooth perovskite film with high coverage. At the cathode, a fullerene bisadduct, C-60(CH2)(Ind), with a shallow lowest unoccupied molecular orbital level, is introduced to replace the commonly used phenyl-C-61-butyric acid methyl ester (PCBM) as an alternative electron transport layer in PVSCs for better energy level matching with the conduction band of the perovskite layer. Therefore, the V-oc, FF and power conversion efficiency (PCE) of the PVSCs increase from 1.05 V, 0.74 and 16.2% to 1.13 V, 0.80 and 18.1% when the PCBM is replaced by C-60(CH2)(Ind). With the advantages of high V-oc and FF, ST-PVSCs are also fabricated using an ultrathin transparent Ag as cathode, showing an encouraging PCEs of 12.6% with corresponding average visible transmittance (AVT) over 20%. These are the highest PCEs reported for ST-PVSCs with similar AVTs paving the way for using ST-PVSCs as power generating windows.

DOI： 10.1002/aenm.201602333

Indium Tin Oxide-free Small Molecule Organic Solar Cells Using Single-walled Carbon Nanotube Electrodes Reviewed International coauthorship Open Access

Clément Delacou, Il Jeon, Seungju Seo, Takafumi Nakagawa, Esko I. Kauppinen, Shigeo Maruyama, Yutaka Matsuo

ECS Journal of Solid State Science and Technology Vol. 6 ( 6 ) page： M3181 - M3184 2017.5

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Electrochemical Society Inc.

We demonstrated single-walled carbon nanotubes (SWNTs) electrode-based small molecule organic solar cells (OSCs) using diketopyrrolopyrrole donor, DPP(TBFu)2 as an electron donor with [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) as an electron acceptor. SWNT films with 60% transmittance (at 550 nm) were dry-transferred onto glass substrates to replace conventional indium tin oxide (ITO) electrodes. In order to improve the conductivity of the SWNT electrodes, MoOx thermal doping was applied followed by spin coating of poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) to enhance doping and electrode blocking function. The indium-free devices showed a power conversion efficiency (PCE) of 1.00% while ITO-based devices showed a PCE of 3.79%.

DOI： 10.1149/2.0311706jss

Open Access

Regioselective acylation and carboxylation of [60] fulleroindoline via electrochemical synthesis Reviewed

Hao-Sheng Lin, Yutaka Matsuo, Jun-Jie Wang, Guan-Wu Wang

ORGANIC CHEMISTRY FRONTIERS Vol. 4 ( 4 ) page： 603 - 607 2017.4

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

A regioselective and highly efficient electrochemical method for direct acylation and carboxylation of a [60] fulleroindoline has been developed. By using inexpensive and readily available acyl chlorides and chloroformates, both keto and ester groups can be easily attached onto the fullerene skeleton to afford 1,2,3,16-functionalized [60] fullerene derivatives regioselectively. In addition, a plausible mechanism for the formation of fullerenyl ketones and esters is proposed, and their further transformations under basic and acidic conditions have been investigated.

DOI： 10.1039/c6qo00654j

An efficient organic solvent-free solution-processing strategy for high-mobility metal chalcogenide film growth Reviewed

Structures and properties of Saturn-like complexes composed of oligothiophene macrocycle with methano[60]fullerene and [70]fullerene Reviewed Open Access

Iyoda Masahiko, Shimizu Hideyuki, Aoyagi Shinobu, Okada Hiroshi, Zhou Biao, Matsuo Yutaka

CANADIAN JOURNAL OF CHEMISTRY Vol. 95 ( 3 ) page： 315 - 319 2017.3

Jie Zhao, Il Jeon, Qinghua Yi, Menka Jain, Mark H. Rummeli, Pingyuan Song, Yutaka Matsuo, Guifu Zou

GREEN CHEMISTRY Vol. 19 ( 4 ) page： 946 - 951 2017.2

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

One of the primary challenges for high-quality metal chalcogenide film growth by a chemical solution approach is to avoid the use of volatile/hazardous organic solvents during the fabrication processes. Herein, we demonstrate an organic solvent-free solution processing method which has the ability to enable growth of a diverse range of metal chalcogenide films. The processing solution is prepared by combining the required metal ions with non-volatile and non-flammable ionic liquid precursor solutions. These stable and homogeneous solutions can form a variety of high-quality and uniform metal chalcogenide films. Due to the facile and instant control of the stoichiometry used in this method, the band gap of multi-element compound semiconductors, for example quinary Cu2ZnSn( S, Se) (4), can be easily tuned from 1.01 eV of Cu2ZnSnSe4 to 1.52 eV of Cu2ZnSnS4. The resulting film also shows high hole mobility with a maximum of 56.9 cm(2) V-1 s(-1) for a carrier concentration of 3.24 x 10(16) cm(-3) at room temperature. Cu2ZnSnS4-based solar cells displayed an efficiency of 5.68%, which is comparable to the reported efficiencies of solar cells prepared by methods involving organic solvents ( 5.0-6.4%).

DOI： 10.1039/c6gc02489k

Fullerene Cation-mediated Demethylation/Cyclization to give 5- and 7-Membered Cyclo[60]fullerene Derivatives Reviewed

Polymer-Fullerene Solar Cells Reviewed

Il Jeon, Yutaka Matsuo

Encyclopedia of Polymer Science and Technology page： 1 - 17 2017.2

Yutaka Matsuo, Keisuke Ogumi, Ying Zhang, Hiroshi Okada, Takafumi Nakagawa, Hiroshi Ueno, Akiko Gocho, Eiichi Nakamura

JOURNAL OF MATERIALS CHEMISTRY A Vol. 5 ( 6 ) page： 2774 - 2783 2017.2

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Single-bonded fullerene dimers, (C60R)(2) (R = (2-methoxyphenyl)dimethylsilylmethyl, (isopropoxy) dimethylsilylmethyl, and 2-methoxy-5-methylphenyl), afforded fullerene derivative cations (RC60+) in the presence of an oxidant (I-2, CuCl2, or CuBr2), leading to 5- and 7-membered cyclo[60]fullerene derivatives such as cyclo[60]fullerenes containing a Si-O bond, cyclo[60]fullerenes containing a C-60-O bond, and dihydrobenzofurano[60]fullerene. The reaction mechanism involved thermal homolytic cleavage to give fullerene radicals, oxidation of the radicals to generate fullerene cations, and then demethylative cyclization in which the fullerene cationic centers interact with an aromatic group or the oxygen atoms of methoxy groups to produce the cyclized products. The obtained cyclo[60]fullerene derivatives were used in bulk-heterojunction organic solar cells and showed moderate power conversion efficiency and respectable open-circuit voltage.

DOI： 10.1039/c6ta10319g