東北大学金属材料研究所助教授

2000年2月 - 2007年3月

ドレスデン工大応用光物理研究所客員研究員

1998年3月 - 1999年1月

東京大学先端科学技術研究センター助手

1994年7月 - 2000年1月

International Advisory Committee of World Conference on Photovoltaic Energy Conversion   member  

2020年8月 - 現在   

The 8th Asian Conference on Crystal Growth and Crystal Technology   Co-Chair of Program and Award Selection Committee  

2019年 - 2021年3月   

The 33rd International Photovoltaic Science and Engineering Conference   General Chair of Organizing Committee  

2018年12月 - 現在   

The 10th International Workshop on Crystalline Silicon for Solar Cells   Co-Chair of the organizing committee  

2016年4月 - 2016年8月   

日本学術振興会結晶加工と評価技術第145委員会   幹事  

2013年 - 現在   

日本学術振興会次世代の太陽光発電システム第175委員会   副委員長  

2009年 - 2020年3月   

International Advisory Committee of the International Workshop on Crystalline Silicon for Solar Cells   member  

2006年10月 - 現在   

日本学術振興会結晶成長の科学と技術第161委員会   幹事長代理  

2000年 - 現在   

インテリジェント・コスモス奨励賞

2008年8月   財団法人インテリジェント・コスモス学術振興財団  

安藤博記念学術奨励賞

2000年7月   一般財団法人安藤研究所  

Engineering Conference Foundation Fellowship on Silicon Heterostructrues

1997年9月  

Young Researcher Award of International Conference on Solid State Devices and Materials

1993年8月  

Origin of recombination activity of non-coherent sigma 3{111} grain boundaries with a positive deviation in the tilt angle in cast-grown silicon ingots 査読有り 国際誌

Ohno Yutaka, Tamaoka Takehiro, Yoshida Hideto, Shimizu Yasuo, Kutsukake Kentaro, Nagai Yasuyoshi, Usami Noritaka

APPLIED PHYSICS EXPRESS   14 巻 ( 1 ) 頁： .   2021年1月

Activation energy of hydrogen desorption from high-performance titanium oxide carrier-selective contacts with silicon oxide interlayers 査読有り 国際誌

Gotoh Kazuhiro, Mochizuki Takeya, Hojo Tomohiko, Shibayama Yuki, Kurokawa Yasuyoshi, Akiyama Eiji, Usami Noritaka

CURRENT APPLIED PHYSICS   21 巻   頁： 36 - 42   2021年1月

The impact of highly excessive PbI2 on the correlation of MAPbI(3) perovskite morphology and carrier lifetimes 査読有り 国際共著 国際誌

Van Hoang Nguyen, Hoang Tuan K. A., Kurokawa Yasuyoshi, Usami Noritaka

JOURNAL OF MATERIALS CHEMISTRY C   8 巻 ( 41 ) 頁： 14481 - 14489   2020年11月

Generation of dislocation clusters at triple junctions of random angle grain boundaries during cast growth of silicon ingots 査読有り 国際誌

Ohno Yutaka, Tajima Kazuya, Kutsukake Kentaro, Usami Noritaka

APPLIED PHYSICS EXPRESS   13 巻 ( 10 )   2020年10月

Determination of carrier recombination velocity at inclined grain boundaries in multicrystalline silicon through photoluminescence imaging and carrier simulation 査読有り 国際誌

Mitamura Kazuki, Kutsukake Kentaro, Kojima Takuto, Usami Noritaka

JOURNAL OF APPLIED PHYSICS   128 巻 ( 12 )   2020年9月

Impact of Ge deposition temperature on parameters of c-Si solar cells with surface texture formed by etching of Si using SiGe islands as a mask 査読有り 国際共著 国際誌

Nguyen V. H., Novikov A., Shaleev M., Yurasov D., Semma M., Gotoh K., Kurokawa Y., Usami N.

MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING   114 巻   2020年8月

Reactive deposition growth of highly (001)-oriented BaSi2 films by close-spaced evaporation 査読有り 国際誌

Hara Kosuke O., Takizawa Shuhei, Yamanaka Junji, Usami Noritaka, Arimoto Keisuke

MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING   113 巻   2020年7月

Atomic hydrogen passivation for photoresponsivity enhancement of boron-doped p-BaSi2 films and performance improvement of boron-doped p-BaSi2/n-Si heterojunction solar cells 査読有り 国際共著 国際誌

Xu Zhihao, Sato Takuma, Benincasa Louise, Yamashita Yudai, Deng Tianguo, Gotoh Kazuhiro, Toko Kaoru, Usami Noritaka, Filonov Andrew B., Migas Dmitri B., Shohonov Denis A., Suemasu Takashi

JOURNAL OF APPLIED PHYSICS   127 巻 ( 23 )   2020年6月

Impact of deposition of indium tin oxide double layers on hydrogenated amorphous silicon/crystalline silicon heterojunction 査読有り

Semma Masanori, Gotoh Kazuhiro, Wilde Markus, Ogura Shohei, Kurokawa Yasuyoshi, Fukutani Katsuyuki, Usami Noritaka

AIP ADVANCES   10 巻 ( 6 )   2020年6月

Significant enhancement of photoresponsivity in As-doped n-BaSi2 epitaxial films by atomic hydrogen passivation 査読有り 国際誌

Aonuki Sho, Yamashita Yudai, Sato Takuma, Xu Zhihao, Gotoh Kazuhiro, Toko Kaoru, Terai Yoshikazu, Usami Noritaka, Suemasu Takashi

APPLIED PHYSICS EXPRESS   13 巻 ( 5 ) 頁： .   2020年5月

Undoped p-type BaSi2 emitter prepared by thermal evaporation and post-annealing for crystalline silicon heterojunction solar cells 査読有り 国際誌

Kimura Yuki, Gotoh Kazuhiro, Kurokawa Yasuyoshi, Usami Noritaka

APPLIED PHYSICS EXPRESS   13 巻 ( 5 )   2020年5月

Scalable fabrication of GaN on amorphous substrates via MOCVD on highly oriented silicon seed layers 査読有り 国際共著 国際誌

Hainey Mel Jr., Robin Yoann, Avit Geoffrey, Amano Hiroshi, Usami Noritaka

JOURNAL OF CRYSTAL GROWTH   535 巻   2020年4月

3D visualization of growth interfaces in cast Si ingot using inclusions distribution 査読有り 国際共著 国際誌

Kamibeppu Soichiro, Krenckel Patricia, Troetschler Theresa, Hess Adam, Riepe Stephan, Usami Noritaka

JOURNAL OF CRYSTAL GROWTH   535 巻   2020年4月

Drastic enhancement of photoresponsivity in C-doped BaSi2 films formed by radio-frequency sputtering 査読有り 国際誌

Nemoto T., Matsuno S., Sato T., Gotoh K., Mesuda M., Kuramochi H., Toko K., Usami N., Suemasu T.

JAPANESE JOURNAL OF APPLIED PHYSICS   59 巻   2020年4月

Synthesis of Mg2Si thin film by thermal treatment under inert gas atmosphere and evaluation of film quality

Horiba Issei, Fujiwara Michinobu, Nakagawa Yoshihiko, Gotoh Kazuhiro, Kurokawa Yasuyoshi, Itoh Takashi, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   59 巻   2020年4月

Surface inversion layer effective minority carrier mobility as one of the measures of surface quality of the p-aSi:H/i-aSi:H/cSi heterojunction solar cell

Kamioka Takefumi, Hayashi Yutaka, Gotoh Kazuhiro, Ozaki Ryo, Nakamura Kyotaro, Morimura Motoo, Naitou Shimako, Usami Noritaka, Ogura Atsushi, Ohshita Yoshio

JAPANESE JOURNAL OF APPLIED PHYSICS   59 巻   2020年4月

Preparation and thermoelectric characterization of phosphorus-doped Si nanocrystals/silicon oxide multilayers

Kobayashi Hisayoshi, Akaishi Ryushiro, Kato Shinya, Kurosawa Masashi, Usami Noritaka, Kurokawa Yasuyoshi

JAPANESE JOURNAL OF APPLIED PHYSICS   59 巻   2020年4月

Influence of the time-dependent vapor composition on structural properties of the BaSi2 thin films fabricated by vacuum evaporation

Yoshino Takamasa, Nakagawa Yoshihiko, Kimura Yuki, Fujiwara Michinobu, Kurokawa Yasuyoshi, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   59 巻   2020年4月

Fabrication of group IV semiconductor alloys on Si substrate applying Al paste with screen-printing

Nakahara Masahiro, Matsubara Moeko, Suzuki Shota, Dhamrin Marwan, Miyamoto Satoru, Hainey Mel Forrest Jr., Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   59 巻   2020年4月

Effects of evaporation vapor composition and post-annealing conditions on carrier density of undoped BaSi2 evaporated films 査読有り 国際誌

Kimura Yuki, Fujiwara Michinobu, Nakagawa Yoshihiko, Gotoh Kazuhiro, Kurokawa Yasuyoshi, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   59 巻   2020年4月

Effect of Si substrate modification on improving the crystalline quality, optical and electrical properties of thermally-evaporated BaSi2 thin-films for solar cell applications 査読有り 国際共著 国際誌

Mai Thi Kieu Lien, Usami Noritaka

INTERNATIONAL JOURNAL OF MODERN PHYSICS B   34 巻 ( 8 )   2020年3月

Surface-orientation control of silicon thin films via aluminum-induced crystallization on monocrystalline cubic substrates 国際共著

Hainey Mel Jr., Zhou Eddie (Chenhui), Viguerie Loic, Usami Noritaka

JOURNAL OF CRYSTAL GROWTH   533 巻   2020年3月

Effect of hydrogen plasma treatment on the passivation performance of TiOx on crystalline silicon prepared by atomic layer deposition 査読有り 国際誌

Miyagawa Shinsuke, Gotoh Kazuhiro, Ogura Shohei, Wilde Markus, Kurokawa Yasuyoshi, Fukutani Katsuyuki, Usami Noritaka

JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A   38 巻 ( 2 )   2020年3月

Effect of forming gas annealing on hydrogen content and surface morphology of titanium oxide coated crystalline silicon heterocontacts 査読有り 国際誌

Nakagawa Yuta, Gotoh Kazuhiro, Wilde Markus, Ogura Shohei, Kurokawa Yasuyoshi, Fukutani Katsuyuki, Usami Noritaka

JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A   38 巻 ( 2 )   2020年3月

Point defects in BaSi2 thin films for photovoltaic applications studied by positron annihilation spectroscopy 国際共著

Montes A., Eijt S. W. H., Tian Y., Gram R., Schut H., Suemasu T., Usami N., Zeman M., Serra J., Isabella O.

JOURNAL OF APPLIED PHYSICS   127 巻 ( 8 )   2020年2月

Effect of the Niobium-Doped Titanium Oxide Thickness and Thermal Oxide Layer for Silicon Quantum Dot Solar Cells as a Dopant-Blocking Layer 査読有り 国際誌

Akaishi Ryushiro, Kitazawa Kohei, Gotoh Kazuhiro, Kato Shinya, Usami Noritaka, Kurokawa Yasuyoshi

NANOSCALE RESEARCH LETTERS   15 巻 ( 1 )   2020年2月

Application of artificial neural network to optimize sensor positions for accurate monitoring: an example with thermocouples in a crystal growth furnace 査読有り 国際誌

Boucetta Abderahmane, Kutsukake Kentaro, Kojima Takuto, Kudo Hiroaki, Matsumoto Tetsuya, Usami Noritaka

APPLIED PHYSICS EXPRESS   12 巻 ( 12 )   2019年12月

Tuning the Electrical Properties of Titanium Oxide Bilayers Prepared by Atomic Layer Deposition at Different Temperatures

Gotoh Kazuhiro, Mochizuki Takeya, Kurokawa Yasuyoshi, Usami Noritaka

PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE   216 巻 ( 22 )   2019年11月

Mossbauer spectroscopic microscope study on diffusion and segregation of Fe impurities in mc-Si wafer 査読有り

Yoshida Yutaka, Watanabe Tomio, Ino Yuji, Kobayashi Masashi, Takahashi Isao, Usami Noritaka

HYPERFINE INTERACTIONS   240 巻 ( 1 )   2019年9月

Hydrogen concentration at a-Si:H/c-Si heterointerfaces-The impact of deposition temperature on passivation performance

Gotoh Kazuhiro, Wilde Markus, Kato Shinya, Ogura Shohei, Kurokawa Yasuyoshi, Fukutani Katsuyuki, Usami Noritaka

AIP ADVANCES   9 巻 ( 7 )   2019年7月

Marked enhancement of the photoresponsivity and minority-carrier lifetime of BaSi2 passivated with atomic hydrogen 国際共著

Xu Zhihao, Shohonov Denis A., Filonov Andrew B., Gotoh Kazuhiro, Deng Tianguo, Honda Syuta, Toko Kaoru, Usami Noritaka, Migas Dmitri B., Borisenko Victor E., Suemasu Takashi

PHYSICAL REVIEW MATERIALS   3 巻 ( 6 )   2019年6月

Evidence of solute PEDOT:PSS as an efficient passivation material for fabrication of hybrid c-Si solar cells 査読有り 国際誌

Van Hoang Nguyen, Kato Shinya, Gotoh Kazuhiro, Kurokawa Yasuyoshi, Usami Noritaka

SUSTAINABLE ENERGY & FUELS   3 巻 ( 6 ) 頁： 1448 - 1454   2019年6月

Impact of size distributions of Ge islands as etching masks for anisotropic etching on formation of anti-reflection structures 国際共著

Ota Yushi, Yurasov Dmitry, Novikov Alexey, Shaleev Mikhail, Gotoh Kazuhiro, Kurokawa Yasuyoshi, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   58 巻 ( 4 )   2019年4月

Epitaxial growth of SiGe on Si substrate by printing and firing of Al-Ge mixed paste 査読有り 国際誌

Fukami Shogo, Nakagawa Yoshihiko, Hainey Mel E. Jr., Gotoh Kazuhiro, Kurokawa Yasuyoshi, Nakahara Masahiro, Dhamrin Marwan, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   58 巻 ( 4 )   2019年4月

Local Structure of High Performance TiOx Electron-Selective Contact Revealed by Electron Energy Loss Spectroscopy 査読有り

Mochizuki Takeya, Gotoh Kazuhiro, Kurokawa Yasuyoshi, Yamamoto Takahisa, Usami Noritaka

ADVANCED MATERIALS INTERFACES   6 巻 ( 3 )   2019年2月

Pole figure analysis from electron backscatter diffraction-an effective method of evaluating fiber-textured silicon thin films as seed layers for epitaxy 査読有り

Hainey Mel Jr., Robin Yoann, Amano Hiroshi, Usami Noritaka

APPLIED PHYSICS EXPRESS   12 巻 ( 2 )   2019年2月

3D visualization and analysis of dislocation clusters in multicrystalline silicon ingot by approach of data science 査読有り

Hayama Yusuke, Matsumoto Tetsuya, Muramatsu Tetsuro, Kutsukake Kentaro, Kudo Hiroaki, Usami Noritaka

SOLAR ENERGY MATERIALS AND SOLAR CELLS   189 巻   頁： 239-244   2019年1月

Fabrication of Si1-xGex layer on Si substrate by Screen-Printing 査読有り

Nakahara Masahiro, Matsubara Moeko, Suzuki Shota, Fukami Shogo, Dhamrin Manvan, Usami Noritaka

MRS ADVANCES   4 巻 ( 13 ) 頁： 749-754   2019年

Effects of Surface Doping of Si Absorbers on the Band Alignment and Electrical Performance of TiO2-Based Electron-Selective Contacts 査読有り

Lee Hyunju, Kamioka Takefumi, Usami Noritaka, Ohshita Yoshio

MRS ADVANCES   4 巻 ( 13 ) 頁： 769-775   2019年

Significant improvement on electrical properties of BaSi2 due to atomic H passivation by radio-frequency plasma 査読有り

Xu Zhihao, Gotoh Kazuhiro, Deng Tianguo, Toko Kaoru, Usami Noritaka, Suemasu Takashi

2019 IEEE 46TH PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC)     頁： 12-14   2019年

Fine Line Al Printing on Narrow Point Contact Opening for Front Side Metallization 査読有り

Tsuji Kosuke, Suzuki Shota, Morishita Naoya, Kuroki Takashi, Nakahara Masahiro, Dhamrin Marwan, Peng Zih-Wei, Buck Thomas, Usami Noritaka

9TH INTERNATIONAL CONFERENCE ON CRYSTALLINE SILICON PHOTOVOLTAICS (SILICONPV 2019)   2147 巻   2019年

Optimized electrical control of a Si/SiGe spin qubit in the presence of an induced frequency shift 査読有り 国際共著

Takeda K., Yoneda J., Otsuka T., Nakajima T., Delbecq M. R., Allison G., Hoshi Y., Usami N., Itoh K. M., Oda S., Kodera T., Tarucha S.

NPJ QUANTUM INFORMATION   4 巻   2018年10月

Application of weighted Voronoi diagrams to analyze nucleation sites of multicrystalline silicon ingots 査読有り

Muramatsu Tetsuro, Hayama Yusuke, Kutsukake Kentaro, Maeda Kensaku, Matsumoto Tetsuya, Kudo Hiroaki, Fujiwara Kozo, Usami Noritaka

JOURNAL OF CRYSTAL GROWTH   499 巻   頁： 62-66   2018年10月

Fabrication and properties characterization of BaSi2 thin-films thermally-evaporated on Ge (100) modified substrates 査読有り

Mai Thi Kieu Lien, Nakagawa Yoshihiko, Kurokawa Yasuyoshi, Usami Noritaka

THIN SOLID FILMS   663 巻   頁： 14-20   2018年10月

Activation mechanism of TiOx passivating layer on crystalline Si

Mochizuki Takeya, Gotoh Kazuhiro, Ohta Akio, Ogura Shohei, Kurokawa Yasuyoshi, Miyazaki Seiichi, Fukutani Katsuyuki, Usami Noritaka

APPLIED PHYSICS EXPRESS   11 巻 ( 10 )   2018年10月

Fabrication of light-trapping structure by selective etching of thin Si substrates masked with a Ge dot layer and nanomasks 査読有り

Hombe Atsushi, Kurokawa Yasuyoshi, Gotoh Kazuhiro, Akagi Seimei, Yamamoto Yuzo, Yurasov Dmitry, Novikov Alexey, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   57 巻 ( 8 )   2018年8月

Investigation of effective near-infrared light-trapping structure with submicron diameter for crystalline silicon thin film solar cells

Sei Miki, Kurokawa Yasuyoshi, Kato Shinya, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   57 巻 ( 8 )   2018年8月

Influence of barrier layer's height on the performance of Si quantum dot solar cells 査読有り

Kitazawa Kouhei, Akaishi Ryushiro, Ono Satoshi, Takahashi Isao, Usami Noritaka, Kurokawa Yasuyoshi

JAPANESE JOURNAL OF APPLIED PHYSICS   57 巻 ( 8 )   2018年8月

Impact of boron incorporation on properties of silicon solar cells employing p-type polycrystalline silicon grown by aluminum-induced crystallization

Masuda Shota, Gotoh Kazuhiro, Takahashi Isao, Nakamura Kyotaro, Ohshita Yoshio, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   57 巻 ( 8 )   2018年8月

Formation of light-trapping structure using Ge islands grown by gas-source molecular beam epitaxy as etching masks

Ota Yushi, Hombe Atsushi, Nezasa Ryota, Yurasov Dmitry, Novikov Alexey, Shaleev Mikhail, Baidakova Natalie, Morozova Elena, Kurokawa Yasuyoshi, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   57 巻 ( 8 )   2018年8月

Photovoltaic Science and Engineering FOREWORD

Matsubara Koji, Yamada Akira, Minemoto Takashi, Itoh Takashi, Arafune Koji, Fujiwara Hiroyuki, Hayase Shuzi, Hiramoto Masahiro, Hishikawa Yoshihiro, Imaizumi Mitsuru, Ito Masakazu, Kaizuka Izumi, Kato Takuya, Komoto Keiichi, Kubo Takaya, Maitani Masato, Masuda Atsushi, Miyajima Shinsuke, Morita Kengo, Negami Takayuki, Ogimoto Kazuhiko, Ohdaira Keisuke, Ohshita Yoshio, Okada Yoshitaka, Okamoto Tamotsu, Osaka Itaru, Sai Hitoshi, Sakurai Takeaki, Shen Qing, Shibata Hajima, Sugaya Takeyoshi, Sugiyama Mutsumi, Takamoto Tatsuya, Tanaka Tooru, Terakawa Akira, Ueda Yuzuru, Usami Noritaka, Wakao Shinji, Yagi Shuhei, Yamanaka Sanshiro, Yoshida Yuji, Yoshita Masahiro

JAPANESE JOURNAL OF APPLIED PHYSICS   57 巻 ( 8 )   2018年8月

Effect of substrate type on the electrical and structural properties of TiO2 thin films deposited by reactive DC sputtering

Cheng Xuemei, Gotoh Kazuhiro, Nakagawa Yoshihiko, Usami Noritaka

JOURNAL OF CRYSTAL GROWTH   491 巻   頁： 120-125   2018年6月

Improving the photoresponse spectra of BaSi2 layers by capping with hydrogenated amorphous Si layers prepared by radio-frequency hydrogen plasma

Xu Zhihao, Gotoh Kazuhiro, Deng Tianguo, Sato Takuma, Takabe Ryota, Toko Kaoru, Usami Noritaka, Suemasu Takashi

AIP ADVANCES   8 巻 ( 5 )   2018年5月

BaSi2 formation mechanism in thermally evaporated films and its application to reducing oxygen impurity concentration

Hara Kosuke O., Yamamoto Chiaya, Yamanaka Junji, Arimoto Keisuke, Nakagawa Kiyokazu, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   57 巻 ( 4 )   2018年4月

Simple method for significant improvement of minority-carrier lifetime of evaporated BaSi₂ thin film by sputtered-AlOx passivation

N.M. Shaalan, K.O. Hara, C.T. Trinh, Y. Nakagawa, and N. Usami

Materials Science in Semiconductor Processing   76 巻   頁： 37-41   2018年3月

Simple method for significant improvement of minority-carrier lifetime of evaporated BaSi2 thin film by sputtered-AlOx passivation

Shaalan N. M., Hara K. O., Trinh C. T., Nakagawa Y., Usami N.

MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING   76 巻   頁： 37 - 41   2018年3月

Formation of black silicon using SiGe self-assembled islands as a mask for selective anisotropic etching of silicon

D. V. Yurasov, A. V. Novikov, M. V. Shaleev, N. A. Baidakova, E. E. Morozova, E. V. Skorokhodov, Y. Ota, A. Hombe, Y. Kurokawa, and N. Usami

Materials Science in Semiconductor Processing   ( 75 ) 頁： 143-148   2018年3月

Formation of black silicon using SiGe self-assembled islands as a mask for selective anisotropic etching of silicon

Yurasov D. V., Novikov A. V., Shaleev M. V., Baidakova N. A., Morozova E. E., Skorokhodov E. V., Ota Y., Hombe A., Kurokawa Y., Usami N.

MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING   75 巻   頁： 143 - 148   2018年3月

BaSi₂ formation mechanism in thermally-evaporated films and its application to reducing oxygen impurity concentration

K.O. Hara, C. Yamamoto, J. Yamanaka, K. Arimoto, K. Nakagawa, and N. Usami

Japanese Journal of Applied Physics   ( 57 ) 頁： 04FS01   2018年2月

A quantum-dot spin qubit with coherence limited by charge noise and fidelity higher than 99.9%

Yoneda Jun, Takeda Kenta, Otsuka Tomohiro, Nakajima Takashi, Delbecq Matthieu R., Allison Giles, Honda Takumu, Kodera Tetsuo, Oda Shunri, Hoshi Yusuke, Usami Noritaka, Itoh Kohei M., Tarucha Seigo

NATURE NANOTECHNOLOGY   13 巻 ( 2 ) 頁： 102 - +   2018年2月

Alternative simple method to realize p-type BaSi2 thin films for Si heterojunction solar cell applications

Takahashi Kazuma, Nakagawa Yoshihiko, Hara Kosuke O., Takahashi Isao, Kurokawa Yasuyoshi, Usami Noritaka

MRS ADVANCES   3 巻 ( 25 ) 頁： 1435-1442   2018年

Suppression of Near-interface Oxidation in Thermally-evaporated BaSi2 Films and Its Effects on Preferred Orientation and the Rectification Behavior of n-BaSi2/p(+)-Si Diodes

Hara Kosuke O., Arimoto Keisuke, Yamanaka Junji, Nakagawa Kiyokazu, Usami Noritaka

MRS ADVANCES   3 巻 ( 25 ) 頁： 1387-1392   2018年

Fabrication of silicon nanowire based solar cells using TiO2/Al2O3 stack thin films

Kurokawa Yasuyoshi, Nezasa Ryota, Kato Shinya, Miyazaki Hisashi, Takahashi Isao, Usami Noritaka

MRS ADVANCES   3 巻 ( 25 ) 頁： 1419-1426   2018年

Local Structure of High Performance TiOx Passivating Layer Revealed by Electron Energy Loss Spectroscopy

Mochizuki Takeya, Gotoh Kazuhiro, Ohta Akio, Kurokawa Yasuyoshi, Miyazaki Seiichi, Yamamoto Takahisa, Usami Noritaka

2018 IEEE 7TH WORLD CONFERENCE ON PHOTOVOLTAIC ENERGY CONVERSION (WCPEC) (A JOINT CONFERENCE OF 45TH IEEE PVSC, 28TH PVSEC & 34TH EU PVSEC)     頁： 3896-3899   2018年

Photoresponsivity improvement of BaSi2 epitaxial films by capping with hydrogenated amorphous Si layers by radio-frequency H-2 plasma

Xu Zhihao, Gotoh Kazuhiro, Deng Tianguo, Sato Takuma, Toko Kaoru, Usami Noritaka, Suemasu Takashi

2018 IEEE 7TH WORLD CONFERENCE ON PHOTOVOLTAIC ENERGY CONVERSION (WCPEC) (A JOINT CONFERENCE OF 45TH IEEE PVSC, 28TH PVSEC & 34TH EU PVSEC)     頁： 1871-1873   2018年

Evaluation of Si Nanowire MOS Capacitor Using High-k Dielectric Materials

Nezasa R., Kurokawa Y., Usami N.

2018 IEEE 18TH INTERNATIONAL CONFERENCE ON NANOTECHNOLOGY (IEEE-NANO)     頁： .   2018年

Development of the Passivation Layer For P-type CuI Thin Film Fabricated by the 2-step Method as the Novel Hole Selective Contact of Silicon Heterojunction Solar Cells

Cui Min, Gotoh Kazuhiro, Kurokawa Yasuyoshi, Usami Noritaka

2018 IEEE 7TH WORLD CONFERENCE ON PHOTOVOLTAIC ENERGY CONVERSION (WCPEC) (A JOINT CONFERENCE OF 45TH IEEE PVSC, 28TH PVSEC & 34TH EU PVSEC)     頁： 2118-2120   2018年

Deposition and Characterization of Si Quantum Dot Multilayers Prepared by Plasma Enhanced Chemical Vapor Deposition using SiH4 and CO2 Gases

Akaishi Ryushiro, Kitazawa Kouhei, Ono Satoshi, Gotoh Kazuhiro, Ichihara Eiji, Kato Shinya, Usami Noritaka, Kurokawa Yasuyoshi

2018 IEEE 7TH WORLD CONFERENCE ON PHOTOVOLTAIC ENERGY CONVERSION (WCPEC) (A JOINT CONFERENCE OF 45TH IEEE PVSC, 28TH PVSEC & 34TH EU PVSEC)     頁： 2852-2856   2018年

Controllable Optical and Electrical Properties of Nb Doped TiO2 Films by RF Sputtering

Cheng Xuemei, Gotoh Kazuhiro, Mochizuki Takeya, Usami Noritaka

2018 IEEE 7TH WORLD CONFERENCE ON PHOTOVOLTAIC ENERGY CONVERSION (WCPEC) (A JOINT CONFERENCE OF 45TH IEEE PVSC, 28TH PVSEC & 34TH EU PVSEC)     頁： 1986-1990   2018年

Application of light trapping structure using Ge dot mask by alkaline etching to heterojunction solar cell

Hombe Atsushi, Kurokawa Yasuyoshi, Gotoh Kazuhiro, Usami Noritaka

2018 IEEE 7TH WORLD CONFERENCE ON PHOTOVOLTAIC ENERGY CONVERSION (WCPEC) (A JOINT CONFERENCE OF 45TH IEEE PVSC, 28TH PVSEC & 34TH EU PVSEC)     頁： 3097-3101   2018年

Investigation on the origin of preferred a-axis orientation of BaSi2 films deposited on Si(100) by thermal evaporation

Hara Kosuke O., Yamamoto Chiaya, Yamanaka Junji, Arimoto Keisuke, Nakagawa Kiyokazu, Usami Noritaka

MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING   72 巻   頁： 93-98   2017年12月

Selective etching of Si, SiGe, Ge and its usage for increasing the efficiency of silicon solar cells

Baidakova N. A., Verbus V. A., Morozova E. E., Novikov A. V., Skorohodov E. V., Shaleev M. V., Yurasov D. V., Hombe A., Kurokawa Y., Usami N.

SEMICONDUCTORS   51 巻 ( 12 ) 頁： 1542 - 1546   2017年12月

Thermal stability of compressively strained Si/relaxed Si₁-xCx heterostructures formed on Ar ion implanted Si (100) substrates

Y. Arisawa, Y. Hoshi, K. Sawano, J. Yamanaka, K. Arimoto, C. Yamamoto, and N. Usami

Materials Science in Semiconductor Processing   ( 70 ) 頁： 127-132   2017年11月

Thermal stability of compressively strained Si/relaxed Si1-xCx heterostructures formed on Ar ion implanted Si (100) substrates

Arisawa You, Hoshi Yusuke, Sawano Kentarou, Yamanaka Junji, Arimoto Keisuke, Yamamoto Chiaya, Usami Noritaka

MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING   70 巻   頁： 127 - 132   2017年11月

Growth of strained Si/relaxed SiGe heterostructures on Si(110) substrates using solid-source molecular beam epitaxy

Arimoto Keisuke, Nakazawa Hiroki, Mitsui Shohei, Utsuyama Naoto, Yamanaka Junji, Hara Kosuke O., Usami Noritaka, Nakagawa Kiyokazu

SEMICONDUCTOR SCIENCE AND TECHNOLOGY   32 巻 ( 11 )   2017年11月

Investigation on the origin of preferred a-axis orientation of BaSi₂ films deposited on Si(100) by thermal evaporation

K. O. Hara, C. Yamamoto, J. Yamanaka, K. Arimoto, K. Nakagawa, and N. Usami

Materials Science in Semiconductor Processing   ( 72 ) 頁： 93-98   2017年10月

Boron-doped p-BaSi2/n-Si solar cells formed on textured n-Si(001) with a pyramid structure consisting of {111} facets

Deng Tianguo, Gotoh Kazuhiro, Takabe Ryota, Xu Zhihao, Yachi Suguru, Yamashita Yudai, Toko Kaoru, Usami Noritaka, Suemasu Takashi

JOURNAL OF CRYSTAL GROWTH   475 巻   頁： 186-191   2017年10月

Formation of metastable cubic phase in SnS thin films fabricated by thermal evaporation

Hara Kosuke O., Suzuki Shintaro, Usami Noritaka

THIN SOLID FILMS   639 巻   頁： 7 - 11   2017年10月

Growth of strained Si/relaxed SiGe heterostructures on Si(110) substrates using solid-source molecular beam epitaxy

K. Arimoto, H. Nakazawa, S. Mitsui, N. Utsuyama, J. Yamanaka, K. O. Hara, N. Usami, and K. Nakagawa

Semiconductor Science and Technology   ( 32 ) 頁： 114002   2017年9月

Fabrication of BaSi2 thin films capped with amorphous Si using a single evaporation source

Hara Kosuke O., Cham Thi Trinh, Kurokawa Yasuyoshi, Arimoto Keisuke, Yamanaka Junji, Nakagawa Kiyokazu, Usami Noritaka

THIN SOLID FILMS   636 巻   頁： 546-551   2017年8月

Formation of metastable cubic phase in SnS thin films fabricated by thermal evaporation

K. O. Hara, S. Suzuki, N. Usami

Thin Solid Films   ( 639 ) 頁： 7-11   2017年8月

Effects of surface morphology randomness on optical properties of Si-based photonic nanostructures

Kurokawa Yasuyoshi, Aonuma Osamu, Tayagaki Takeshi, Takahashi Isao, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   56 巻 ( 8 )   2017年8月

Effect of Surface Morphology Randomness on Optical Properties of Si-based Photonic Nanostructures 査読有り

Y. Kurokawa, O. Aonuma, T. Tayagaki ,I. Takahashi, and N. Usami

Jpn. J. Appl. Phys.   ( 56 ) 頁： 08MA02   2017年7月

Effect of ALD-Al₂O₃ Passivated Silicon Quantum Dot Superlattices on p/i/n⁺ Solar Cells

M. M. Rahman, Yi-Chia Tsai, Ming-Yi Lee, A. Higo, Yiming Li, Y. Hoshi, N. Usami, and S. Samukawa

IEEE TRANSACTIONS ON ELECTRON DEVICES   64 巻   頁： 7   2017年7月

Effect of ALD-Al2O3 Passivated Silicon Quantum Dot Superlattices on p/i/n(+) Solar Cells

Rahman Mohammad Maksudur, Tsai Yi-Chia, Lee Ming-Yi, Higo Akio, Li Yiming, Hoshi Yusuke, Usami Noritaka, Samukawa Seiji

IEEE TRANSACTIONS ON ELECTRON DEVICES   64 巻 ( 7 ) 頁： 2886-2892   2017年7月

On the growth mechanism of multicrystalline silicon ingots with small grains fabricated using single-layer silicon beads

Muramatsu Tetsurou, Takahashi Isao, Babu G. Anandha, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   56 巻 ( 7 )   2017年7月

Effects of grain boundary structure controlled by artificially designed seeds on dislocation generation 査読有り 国際誌

Iwata Taisho, Takahashi Isao, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   56 巻 ( 7 )   2017年7月

Impact of anodic aluminum oxide fabrication and post-deposition anneal on the effective carrier lifetime of vertical silicon nanowires

Van Hoang Nguyen, Sichanugrist Porponth, Kato Shinya, Usami Noritaka

SOLAR ENERGY MATERIALS AND SOLAR CELLS   166 巻   頁： 39 - 44   2017年7月

Fabrication of BaSi₂ thin films capped with amorphous Si using a single evaporation source

K. O. Hara, C. T. Trinh. Y. Kurokawa; K. Arimoto, J. Yamanaka, K. Nakagawa, and N. Usami

Thin Solid Films   ( 646 ) 頁： 546-551   2017年6月

Boron-doped p-BaSi₂/n-Si solar cells formed on textured n-Si(001) with a pyramid structure consisting of {111} facets

T. Deng, K. Gotoh, R. Takabe, Z. Xu, S. Yachi, Y. Yamashita, K. Toko, N. Usami, and T. Suemasu

Journal of Crystal Growth   ( 475 ) 頁： 186-191   2017年6月

Study on ion implantation conditions in fabricating compressively strained Si/relaxed Si₁-_xC_x heterostructures using the defect control by ion implantation technique

Y. Arisawa, K. Sawano, and N. Usami

Journal of Crystal Growth   468 巻   頁： 601-604   2017年6月

Controlling impurity distributions in crystalline Si for solar cells by using artificial designed defects

Hayama Yusuke, Takahashi Isao, Usami Noritaka

JOURNAL OF CRYSTAL GROWTH   468 巻   頁： 610 - 613   2017年6月

Towards optimized nucleation control in multicrystalline silicon ingot for solar cells

G.A.Babu, I.Takahashi, T.Muramatsu, and N.Usami

Journal of Crystal Growth   468 巻   頁： 620-624   2017年6月

Hole mobility in strained Si/SiGe/vicinal Si(110) grown by gas source MBE

K.Arimoto, S.Yagi, J.Yamanaka, K.O.Hara, K.Sawano, N.Usami, and K.Nakagawa

Journal of Crystal Growth   468 巻   頁： 625-629   2017年6月

Controlling Impurity Distribution in Quasi-mono Crystalline Si Ingot by Seed Manipulation for Artificially Controlled Defect Technique

Y. Hayama, I. Takahashi, and N. Usami

Energy Procedia   127 巻   頁： 610-613   2017年6月

Hole mobility in strained Si/SiGe/vicinal Si(110) grown by gas source MBE

Arimoto Keisuke, Yagi Sosuke, Yamanaka Junji, Hara Kosuke O., Sawano Kentarou, Usami Noritaka, Nakagawa Kiyokazu

JOURNAL OF CRYSTAL GROWTH   468 巻   頁： 625 - 629   2017年6月

Towards optimized nucleation control in multicrystalline silicon ingot for solar cells

Babu G. Anandha, Takahashi Isao, Muramatsu Tetsurou, Usami Noritaka

JOURNAL OF CRYSTAL GROWTH   468 巻   頁： 620 - 624   2017年6月

Study on ion implantation conditions in fabricating compressively strained Si/relaxed Si1-xCx heterostructures using the defect control by ion implantation technique

Arisawa You, Sawano Kentarou, Usami Noritaka

JOURNAL OF CRYSTAL GROWTH   468 巻   頁： 601 - 604   2017年6月

On the growth mechanism of multicrystalline silicon ingots with small grains by using single layer silicon beads

T. Muramatsu, I. Takahashi, G. Anandha babu, and N. Usami

Japanese Journal of Applied Physics   ( 56 ) 頁： 075502   2017年6月

Effects of grain boundary structure controlled by artificially designed seeds on dislocation generation

T. Iwata, I. Takahashi, and N. Usami

Japanese Journal of Applied Physics   ( 56 ) 頁： 075501   2017年6月

Minority-carrier lifetime and photoresponse properties of B-doped p-BaSi2, a potential light absorber for solar cells

Bayu M. Emha, Cham Thi Trinh, Takabe Ryota, Yachi Suguru, Toko Kaoru, Usami Noritaka, Suemasu Takashi

JAPANESE JOURNAL OF APPLIED PHYSICS   56 巻 ( 5 )   2017年5月

Growth of BaSi2 film on Ge(100) by vacuum evaporation and its photoresponse properties

Cham Thi Trinh, Nakagawa Yoshihiko, Hara Kosuke O., Kurokawa Yasuyoshi, Takabe Ryota, Suemasu Takashi, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   56 巻 ( 5 )   2017年5月

Investigation of p-type emitter layer materials for heterojunction barium disilicide thin film solar cells

Takahashi Kazuma, Nakagawa Yoshihiko, Hara Kosuke O., Kurokawa Yasuyoshi, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   56 巻 ( 5 )   2017年5月

Postannealing effects on undoped BaSi2 evaporated films grown on Si substrates

Suhara Takamichi, Murata Koichi, Navabi Aryan, Hara Kosuke O., Nakagawa Yoshihiko, Cham Thi Trinh, Kurokawa Yasuyoshi, Suemasu Takashi, Wang Kang L., Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   56 巻 ( 5 )   2017年5月

Growth of BaSi₂ film on Ge(100) by vacuum evaporation and its photoresponse properties 査読有り

C. T. Trinh, Y. Nakagawa, K. O. Hara, Y. Kurokawa, R. Takabe, T. Suemasu, and N. Usami

Jpn. J. Appl. Phys.   ( 56 ) 頁： 05DB06   2017年4月

Postannealing effects on undoped BaSi₂ evaporated films grown on Si substrates 査読有り

T. Suhara, K. Murata, A. Navabi, K. O. Hara, Y. Nakagawa, C. T. Trinh, Y. Kurokawa, T. Suemasu, K. L. Wang, and N. Usami

Jpn. J. Appl. Phys.   ( 56 ) 頁： 05DB05   2017年4月

Investigation of p-type emitter layer materials for heterojunction barium disilicide thin film solar cells 査読有り

K. Takahashi, Y. Nakagawa, K. O. Hara, Y. Kurokawa, and N. Usami

Jpn. J. Appl. Phys.   ( 56 ) 頁： 05DB04   2017年4月

Post-annealing effects on the surface structure and carrier lifetime of evaporated BaSi2 films

Hara Kosuke O., Cham Thi Trinh, Kurokawa Yasuyoshi, Arimoto Keisuke, Yamanaka Junji, Nakagawa Kiyokazu, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   56 巻 ( 4 )   2017年4月

Optical characterization of double-side-textured silicon wafer based on photonic nanostructures for thin-wafer crystalline silicon solar cells

Tayagaki Takeshi, Furuta Daichi, Aonuma Osamu, Takahashi Isao, Hoshi Yusuke, Kurokawa Yasuyoshi, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   56 巻 ( 4 )   2017年4月

Impact of anodic aluminum oxide fabrication and post-deposition anneal on the effective carrier lifetime of vertical silicon nanowires

V. H. Nguyen, P. Sichanugrist, S. Kato, and N. Usami

Solar Energy Materials and Solar Cells   166 巻   頁： 39-44   2017年3月

Post-annealing effects on the surface structure and carrier lifetime of evaporated BaSi₂ films 査読有り

K. O. Hara, C. T. Trinh, Y. Kurokawa, K. Arimoto, J. Yamanaka, K. Nakagawa, and N. Usami

Japanese Journal of Applied Physics   56 巻   頁： 04CS07   2017年3月

Minority-carrier lifetime and photoresponse properties of B-doped p-BaSi₂, a potential light absorber for solar cells 査読有り

M. E. Bayu, C. T. Trinh, R. Takabe, S. Yachi, K. Toko, N. Usami, and T. Suemasu

Jpn. J. Appl. Phys.   ( 56 ) 頁： 05DB01   2017年2月

Optical characterization of double-side-textured silicon wafer based on photonic nanostructures for thin-wafer crystalline silicon solar cells 査読有り

T.Tayagaki, D.Furuta, O.Aonuma, I.Takahashi, Y.Hoshi, Y.Kurokawa, and N.Usami

Japanese Journal of Applied Physics   56 巻   頁： 04CS01   2017年1月

Exploring the potential of semiconducting BaSi2 for thin-film solar cell applications

Suemasu Takashi, Usami Noritaka

JOURNAL OF PHYSICS D-APPLIED PHYSICS   50 巻 ( 2 ) 頁： 1-18   2017年1月

TEM and STEM Observations of a Flat Continuous Silicon-Germanium Thin Film Epitaxially Grown on Porous Silicon 査読有り

J. Yamanaka, N. Usami, S. Amtablian, A. Fave, M. Lemiti, C. Yamamoto, and K. Nakagawa

Journal of Materials Science and Chemical Engineering   5 巻   頁： 26-34   2017年1月

Preferred Orientation of BaSi₂ Thin Films Fabricated by Thermal Evaporation

K. O. Hara, C. T. Trinh, Y. Nakagawa, Y. Kurokawa, K. Arimoto, J. Yamanaka, K. Nakagawa, and N. Usami

JJAP Conference Proceedings   ( 5 ) 頁： 11202   2017年

Realization of Crystalline BaSi₂ Thin Films by Vacuum Evaporation on (111)-oriented Si Layers Fabricated by Aluminum Induced Crystallization

J. A. Wibowo, I. Takahashi, K. O. Hara, and N. Usami

JJAP Conference Proceedings   ( 5 ) 頁： 11201   2017年

Controlling impurity distributions in crystalline Si for solar cells by using artificial designed defects

Y.Hayama, I.Takahashi, and N.Usami

Journal of Crystal Growth   468 巻   頁： 625-629   2017年

Selective Etching of Si, SiGe, Ge and Its Usage for Increasing the Efficiency of Silicon Solar Cells

N.A. Baidakova, V.A. Verbus, E.E. Morozova, A.V. Novikov, E.V. Skorohodov, M.V. Shaleev, D.V. Yurasov, A. Hombe, Y. Kurokawa, and N. Usami

Semiconductors   51 巻 ( 12 ) 頁： 1542-1546   2017年

Development of Spin-coated Copper Iodide Film on Silicon for Use in Hole-selective Contacts

K. Gotoh, M. Cui, I. Takahashi, Y. Kurokawa, and N. Usami

Energy Procedia   124 巻   頁： 598-603   2017年

Controlling impurity distribution in quasi-mono crystalline Si ingot by seed manipulation for artificially controlled defects technique

Hayama Yusuke, Takahashi Isao, Usami Noritaka

7TH INTERNATIONAL CONFERENCE ON SILICON PHOTOVOLTAICS, SILICONPV 2017   124 巻   頁： 734-739   2017年

Development of spin-coated copper iodide on silicon for use in hole-selective contacts

Gotoh Kazuhiro, Cui Min, Takahashi Isao, Kurokawa Yasuyoshi, Usami Noritaka

7TH INTERNATIONAL CONFERENCE ON SILICON PHOTOVOLTAICS, SILICONPV 2017   124 巻   頁： 598-603   2017年

Fabrication of CuI/a-Si:H/c-Si Structure for Application to Hole-selective Contacts of Heterojunction Si Solar Cells

Gotoh Kazuhiro, Cui Min, Thanh Nguyen Cong, Koyama Koichi, Takahashi Isao, Kurokawa Yasuyoshi, Matsumura Hideki, Usami Noritaka

2017 IEEE 44TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC)     頁： 1765-1768   2017年

Solar Cells Application of p-type poly-Si Thin Film by Aluminum Induced Crystallization

Masuda Shota, Gotoh Kazuhiro, Takahashi Isao, Nakamura Kyotaro, Ohshita Yoshio, Usami Noritaka

2017 IEEE 44TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC)     頁： 1794-1796   2017年

Exploring the Potential of Semiconducting BaSi₂ for Thin-Film Solar Cell Applications 査読有り

T. Suemasu and N. Usami

Journal of Physics D: Applied Physics   50 巻   頁： 023001   2016年11月

Effects of the Si/Al layer thickness on the continuity, crystalline orientation and the growth kinetics of the poly-Si thin films formed by aluminum-induced crystallization

S.Tutashkonko, N.Usami

Thin Solid Films   616 巻   頁： 213-219   2016年10月

Growth direction control of dendrite crystals in parallel direction to realize high-quality multicrystalline silicon ingot

T.Hiramatsu, I.Takahashi, S.Matsushima, and N.Usami

Jpn. J. Appl. Phys.   55 巻   頁： 091302   2016年8月

Light-induced recovery of effective carier lifetime in boron-doped Czochralski silicon at room temperature 査読有り

H.Ichikawaa, I.Takahashi, N.Usami, K.Shirasawa, H.Takato

Energy Procedia   92 巻   頁： 801-807   2016年8月

Photoresponse properties of BaSi₂ film grown on Si (100) by vacuum evaporation .

C.T.Trinh, Y.Nakagawa, K.O.Hara, R.Takabe, T.Suemasu, and N.Usami

Materials Research Express   3 巻 ( 7 ) 頁： 076204   2016年7月

Evidence for efficient passivation of vertical silicon nanowires by anodic aluminum oxide

V.H.Nguyen, S.Kato, and N.Usami

Solar Energy Materials and Solar Cells   157 巻   頁： 393-398   2016年7月

Effect of grain boundary character of multicrystalline Si on external and internal (phosphorus) gettering of impurities 査読有り

S.Joonwichien, I.Takahashi, K.Kutsukake, and N.Usami

PROGRESS IN PHOTOVOLTAICS: RESEARCH AND APPLICATIONS     2016年5月

p-BaSi₂/n-Si heterojunction solar cells with conversion efficiency reaching 9.0%

D.Tsukahara, S.Yachi, H.Takeuchi, R.Takabe, W.Du, M.Baba, Y.Li, K.Toko, N.Usami, and T.Suemasu

APPLIED PHYSICS LETTERS   108 巻   頁： 152101   2016年4月

Modulated surface nanostructures for enhanced light trapping and reduced surface reflection of crystalline silicon solar cells 査読有り

T.Tayagaki, Y.Hoshi, Y.Hirai, Y.Matsuo, and N.Usami

Japanese Journal of Applied Physics   ( 55 ) 頁： 52302   2016年4月

Simple vacuum evaporation route to BaSi₂ thin films for solar cell applications 査読有り

K.O.Hara, Y.Nakagawa, T.Suemasu, and N. Usami

Energy Procedia   141 巻   頁： 27-31   2016年3月

On the mechanism of BaSi₂ thin film formation on Si substrate by vacuum evaporation 査読有り

Y.Nakagawaa, K.O.Hara, T.Suemasu, and N.Usami

Energy Procedia   141 巻   頁： 23-26   2016年3月

Improved multicrystalline silicon ingot quality using single layer silicon beads coated with silicon nitride as seed layer

G.Anandha babu, I.Takahashi, S.Matsushima, and N.Usami

Journal of Crystal Growth   441 巻   頁： 124-130   2016年2月

Effect of passivation layer grown by atomic layer deposition and sputtering processes on Si quantum dot superlattice to generate high photocurrent for high-efficiency solar cells

M.M.Rahman, A.Higo, H.Sekhar, M.E.Syazwan, Y.Hoshi, N.Usami, and S.Samukawa

Japanese Journal of Applied Physics   ( 55 ) 頁： 032303   2016年2月

Control of electrical properties of BaSi₂ thin films by alkali-metal doping using alkali-metal fluorides 査読有り

K.O.Hara, W.Du, K.Arimoto, J.Yamanaka, K.Nakagawa, K.Toko, T. Suemasu, and N.Usami

Thin Solid Films   603 巻   頁： 218-223   2016年2月

Compressively strained Si/Si₁_xCx heterostructures formed on Ar ion implanted Si(100) substrates 査読有り

Y.Hoshi, Y.Arisawa, K. Arimoto, J.Yamanaka, K.Nakagawa, K.Sawano, and N.Usami

Japanese Journal of Applied Physics   55 巻   頁： 031302   2016年2月

Impact of silicon quantum dot super lattice and quantum well structure as intermediate layer on p-i-n silicon solar cells

M.M.Rahman, M-Y, Lee, Y-C,Tsai, A. Higo, H.Sekhar, M.Igarashi, M.E.Syazwan, Y.Hoshi, K.Sawano, N.Usami, Y.Li, and S.Samukawa

PROGRESS IN PHOTOVOLTAICS   ( 28 ) 頁： 774-780   2015年12月

Structural and electrical characterizations of crack-free BaSi₂ thin filmsfabricated by thermal evaporation

K.O.Hara, J.Yamanaka, K. Arimoto, K.Nakagawa, T.Suemasu, N.Usami

Thin Solid Films   595 巻   頁： 68-72   2015年10月

Seed manipulation for artificially controlled defect technique in new growth method for quasi-monocrystalline Si ingot based on casting 査読有り

I.Takahashi, S.Joonwichien, T.Iwata, and N.Usami

Applied Physics Express   8 巻   頁： 105501   2015年9月

Selective growth of vertical silicon nanowire array guided by anodic aluminum oxide template 査読有り

V.H.Nguyen, Y.Hoshi, N.Usami, M.Konagai

Japanese Journal of Applied Physics   54 巻   頁： 095003   2015年8月

Comparison of phosphorus gettering effect in faceted dendrite and small grain of multicrystalline silicon wafers grown by floating cast method 査読有り

S.Joonwichien, I.Takahashi, S.Matsushima, N.Usami

Japanese Journal of Applied Physics   54 巻   頁： 08KD11   2015年7月

Application of heterojunction to Si-based solar cells using photonic nanostructures coupled with vertically aligned Ge quantum dots 査読有り

I.Takahashi, Y.Hoshi, T.Tayagaki, T.Oikawa, K.Ohdaira, N.Usami

Japanese Journal of Applied Physics   54 巻   頁： 08KA06   2015年7月

Fabrication of single-phase BaSi₂ thin films on silicon substrates by vacuumevaporation for solar cell applications 査読有り

Y.Nakagawa, K.O.Hara, T.Suemasu, N.Usami

Japanese Journal of Applied Physics   54 巻   頁： 08KC03   2015年7月

Effect of Anodization Process of Aluminum Oxide Template on Selective Growth of Si Nanowires 査読有り

V.H.Nguyen, S.Tutashkonko, Y.Hoshi, N.Usami

Japanese Journal of Applied Physics   54 巻   頁： 08KA02   2015年6月

Geometry in Si-based photonic nanostructures coupled with Ge quantum dot multilayers and its impact on optical properties 査読有り

O.Aonuma, Y.Hoshi, T.Tayagaki, A.Novikov, D.Yurasov, N.Usami

Japanese Journal of Applied Physics   54 巻   頁： 08KA01   2015年6月

Suppression of metastable-phase inclusion in N-polar (0001¯) InGaN/GaN multiple quantum wells grown by metalorganic vapor phase epitaxy 査読有り

K.Shojiki, J-H.Choi, T.Iwabuchi, N.Usami, T.Tanikawa, S.Kuboya, T.Hanada, R.Katayama, T.Matsuoka

Applied Physics Letters   106 巻   頁： 222102   2015年6月

Relationship between dislocation density and contact angle of dendrite crystals in practical size silicon ingot

I.Takahashi, S.Joonwichien, S.Matsushima, N.Usami

Journal of Applied Physics   ( 117 ) 頁： 095701   2015年3月

Realization of single-phase BaSi₂ films by vacuum evaporation with suitable optical properties and carrier lifetime for solar cell applications 査読有り

K.O.Hara, Y.Nakagawa, T.Suemasu, N.Usami

Japanese Journal of Applied Physics   54 巻   頁： 07JE02   2015年3月

Cross-sectional potential profile across a BaSi₂ pn junction by Kelvin probe force microscopy

D.Tsukahara, M.Baba, K.Watanabe, T.Kimura, K.O.Hara, W.Du, N.Usami, K.Toko, T.Sekiguchi, T.Suemasu

Japanese Journal of Applied Physics   54 巻 ( 3 ) 頁： 030306   2015年3月

Cross-sectional potential profile across a BaSi₂ pn junction by Kelvin probe force microscopy 査読有り

D.Tsukahara, M.Baba, K.Watanabe, T.Kimura, K.O.Hara, W.Du, N.Usami, K.Toko, T.Sekiguchi, T.Suemasu

Japanese Journal of Applied Physics   54 巻   頁： 030306   2015年2月

Absorption enhancement in nanotextured solar cells with Ge/Si heterostructures

T.Tayagaki, Y.Kishimoto, Y.Hoshi, N.Usami

Japanese Journal of Applied Physics   ( 54 ) 頁： 04DR03   2015年1月

Influence of Substrate on Crystal Orientation of Large-Grained Si Thin Films Formed by Metal-Induced Crystallization 査読有り

K.Toko, M.Nakata, A.Okada, M.Sasase, N.Usami, T.Suemasu

INTERNATIONAL JOURNAL OF PHOTOENERGY   ( 2015 ) 頁： 790242   2015年1月

バルク結晶成長のこの10年 査読有り

宇治原 徹, 島村清史, 宇佐美 徳隆, 太子 敏則, 樋口 幹雄, 吉村 政志

  42 巻 ( 1 ) 頁： pp.64-68   2015年

Light trapping by direction-dependent light transmission in front-surface photonic nanostructures

T.Tayagaki, Y.Kishimoto, Y.Hoshi, N.Usami

Applied Physics Express   7 巻   頁： 122301   2014年11月

Simulation study of Ge/Si heterostructured solar cells yielding improved open-circuit voltage and quantum efficiency

T.Tayagaki, Y.Kishimoto, Y.Hoshi, I.Takahashi, N.Usami

Japanese Journal of Applied Physics   ( 53 ) 頁： 110312   2014年10月

Potential variations around grain boundaries in impurity-doped BaSi₂ epitaxial films evaluated by Kelvin probe force microscopy

D.Tsukahara, M.Baba, S.Honda, Y.Imai, K.O.Hara, N.Usami, K.Toko, J.H.Werner, T.Suemasu

D.Tsukahara, M.Baba, S.Honda, Y.Imai, K.O.Hara, N.Usami, K.Toko, J.H.Werner, T.Suemasu   116 巻   頁： 123709   2014年9月

Towards implementation of floating cast method for growing large-scale high-quality multicrystalline silicon ingot using designed double crucibles

S.Joonwichien, I.Takahashi, S.Matsushima, N.Usami

PROGRESS IN PHOTOVOLTAICS: RESEARCH AND APPLICATIONS   ( 22 ) 頁： 726-732   2014年7月

Evaluation of minority carrier diffusion length of undoped n-BaSi₂ epitaxial thin films on Si(001) substrates by electron-beam-induced-current technique

M.Baba, K.Watanabe, K.O.Hara, K.Toko, T.Sekiguchi, N.Usami, T.Suemasu

Japanese Journal of Applied Physics   ( 53 ) 頁： 078004   2014年6月

Analysis of the electrical properties of Cr/n-BaSi₂ Schottky junction and n-BaSi2/p-Si heterojunction diodes for solar cell applications

W.D, M.Baba, K.Toko, K.Kosuke, K.Watanabe, T.Sekiguchi, N.Usami, T.Suemasu

Journal of Applied Physics   115 巻   頁： 223701   2014年6月

Analysis of the electrical properties of Cr/n-BaSi₂ Schottky junction and n-BaSi₂/p-Si heterojunction diodes for solar cell applications

W.Du, M.Baba, K.Toko, K.O.Hara, K.Watanabe, T.Sekiguchi, N.Usami, T.Suemasu

Journal of Applied Physics   115 巻   頁： 223701   2014年6月

Influence of grain size and surface condition on minority-carrier lifetime in undoped n-BaSi₂ on Si(111) 査読有り

R.Takabe, K.O.Hara, M.Baba, W.Du, N.Shimada, K.Toko, N.Usami, T.Suemasu

  ( 115 ) 頁： 193510   2014年5月

Carrier extraction dynamics from Ge/Si quantum wells in Si solar cells

T.Tayagaki, Y.Hoshi, K.Ooi, T.Kiguchi, N.Usami

Thin Solid Films   557 巻   頁： 368-371   2014年4月

Control of geometry in Si-based photonic nanostructures formed by maskless wet etching process and its impact on optical properties

Y.Hoshi, T.Tayagaki, T.Kiguchi, N.Usami

Thin Solid Films   557 巻   頁： 338-341   2014年4月

Large-grained (111)-oriented Si/Al/SiO2 structures formed by diffusion-controlled Al-induced layer exchange

R.Numata, K.Toko, N.Usami, T.Suemasu

Thin Solid Films   557 巻   頁： 147-150   2014年4月

Growth promotion of Al-induced crystallized Ge films on insulators by insertion of a Ge membrane below the Al layer

R.Numata, K.Toko, K.Nakazawa, N.Usami, T.Suemasu

Thin Solid Films   557 巻   頁： 143-146   2014年4月

N-type doping of BaSi₂ epitaxial films by phosphorus ion implantation and thermal annealing

K.O.Hara, Y.Hoshi, N.Usami, Y.Shiraki, K.Nakamura, K.Toko, T.Suemasu

Thin Solid Films   557 巻   頁： 90-93   2014年4月

Selective formation of large-grained, (100)- or (111)-oriented Si on glass by Al-induced layer exchange

K.Toko, R.Numata, N.Saitoh, N.Yoshizawa, N.Usami, T.Suemasu

Journal of Applied Physics   115 巻 ( 9 ) 頁： 094301   2014年3月

Formation process of Si₃N₄ particles on surface of Si ingots grown using silica crucibles with Si₃N₄ coating by noncontact crucible method

K.Nakajima, K.Morishita, R.Murai, N.Usami

Journal of Crystal Growth   389 巻   頁： 112-119   2014年3月

Orientation control of Ge thin films by underlayer-selected Al-induced crystallization

K.Toko, K.Nakazawa, N.Saitoh, N.Yoshizawa, N.Usami, T.Suemasu

CrystEngComm   16 巻 ( 13 ) 頁： 2578-2583   2014年2月

Structural characterization of polycrystalline Ge thin films on insulators formed by diffusion-enhanced Al-induced layer exchange

R.Numata, K.Toko, N.Oya, N.Usami and T.Suemasu

Japanese Journal of Applied Physics   53 巻   頁： 04EH03   2014年2月

Al-induced crystallization of amorphous Ge thin films on conducting layer coated glass substrates

K.Nakazawa, K.Toko, N.Usami, T.Suemasu

Japanese Journal of Applied Physics   53 巻   頁： 04EH01   2014年2月

Fabrication and characterization of BaSi₂ epitaxial films over 1 mu m in thickness on Si(111) 査読有り

R.Takabe, K.Nakamura, M.Baba, W.Du, M.A.Khan, K.Toko, M.Sasase, K.Hara, N.Usami, T.Suemasu

Japanese Journal of Applied Physics   53 巻   頁： 04ER04   2014年2月

Enhanced photocarrier generation in large-scale photonic nanostructures fabricated from vertically aligned quantum dots

T.Tayagaki, Y.Hoshi, Y.Kishimoto, and N.Usami

Optics Express   22 巻 ( 52 ) 頁： A225-A232   2014年1月

Low-temperature (180 degrees C) formation of large-grained Ge (111) thin film on insulator using accelerated metal-induced crystallization

K.Toko, R.Numata, N.Oya, N.Fukata, N.Usami, T.Suemasu

Applied Physics Letters   104 巻 ( 2 ) 頁： 022106   2014年1月

Grazing-incidence small-angle X-ray scattering from Ge nanodots self-organized on Si(001) examined with soft X-rays

T.Yamamoto, H.Okuda, K.Takeshita, N.Usami, Y.Kitajima, H.Ogawa

Journal of Synchrotron Radiation   21 巻   頁： 161-164   2014年1月

Mono-Like Silicon Growth Using Functional Grain Boundaries to Limit Area of Multicrystalline Grains

K.kutsukake, N.Usami, Y.Ohno,Y.Tokumoto, I.Yonenaga

Ieee Journal of Photovoltaics   4 巻 ( 1 ) 頁： 84-87   2014年1月

Effect of Ge/Al thickness on Al-induced crystallization of amorphous Ge layers on glass substrates

K.Nakazawa, K.Toko, N.Saitoh, N.Yoshizawa, N.Usami, T.Suemasu

physica status solidi ©   10 巻   頁： 1781-1784   2013年12月

Epitaxial growth of BaSi₂ films with large grains using vicinal Si(111) substrates

M.Baba, K.O.Hara, K.Toko, N.Saito, N.Yoshizawa, N.Usami, T.Suemasu

physica status solidi ©   10 巻   頁： 1756-1768   2013年12月

Investigation of the tunneling properties and surface morphologies of BaSi₂/Si tunnel junctions for BaSi₂ solar cell applications

W.Du, M.Baba, R.Takabe, N.Zhang, K.Toko, N.Usami, T.Suemasu

physica status solidi ©   10 巻   頁： 1765-1768   2013年12月

Fabrication of BaSi₂ films on (111)-oriented Si layers formed by inverted Al-induced crystallization method on glass structure

R.Numata, K.Toko, N.Usami, T.Suemasu

physica status solidi ©   10 巻   頁： 1769-1772   2013年12月

Fabrication and characterizations of phosphorus-doped n-type BaSi₂ epitaxial films grown by molecular beam epitaxy

R.Takabe, M.Baba, K.Nakamura, W.Du, M.A.Khan, S.Koike, K.Toko, K.O.Hara, N.Usami, T.Suemasu

physica status solidi ©   10 巻   頁： 1753-1755   2013年12月

Mechanism of strain relaxation in BaSi₂ epitaxial films on Si(111) substrates during post-growth annealing and application for film exfoliation

K.O.Hara, N.Usami, K.Nakamura, R.Takabe, M.Baba, K.Toko, T.Suemasu

physica status solidi ©   10 巻   頁： 1677-1680   2013年11月

Determination of Bulk Minority-Carrier Lifetime in BaSi₂ Earth-Abundant-Absorber Films by Utilizing a Drastic Enhancement of Carrier Lifetime by Post-Growth Annealing

K.O.Hara, N.Usami, K.Nakamura, R.Takabe, M.Baba, K.Toko, T.Suemasu

Applied Physics Express   6 巻   頁： 112302   2013年11月

Determination of Bulk Minority-Carrier Lifetime in BaSi₂ Earth-Abundant Absorber Films by Utilizing a Drastic Enhancement of Carrier Lifetime by Post-Growth Annealing

K.O.Hara, N.Usami, K.Nakamura, R.Takabe, M.Baba, K.Toko, T.Suemasu

Applied Physics Express   6 巻 ( 11 ) 頁： 112302   2013年10月

Theory of open-circuit voltage and the driving force of charge separation in pn-junction solar cells

K.O.Hara, N.Usami

Journal of Applied Physics   114 巻   頁： 153101   2013年10月

Evaluation of potential variations around grain boundaries in BaSi₂ epitaxial films by Kelvin probe force microscopy

M.Baba, S.Tsurekawa, K.Watanabe, W.Du, K.Toko, K.O.Hara, N.Usami, T.Sekiguchi, T.Suemasu

Applied Physics Letters   103 巻   頁： 142113   2013年9月

Investigation of the open-circuit voltage in solar cells doped with quantum dots

T.Tayagaki, Y.Hoshi, N.Usami

Scientific Reports   3 巻   頁： 2703   2013年9月

Control of Grain Boundary Propagation in Mono-Like Si: Utilization of Functional Grain Boundaries

K.Kutsukake, N.Usami, Y.Ohno, Y.Tokumoto, I.Yonenaga

Applied Physics Express   6 巻   頁： 025505   2013年9月

Effect of atomic-hydrogen irradiation on reduction of residual carrier concentration in β-FeSi₂ films grown on Si substrates by atomic-hydrogen-assisted molecular beam epitaxy

Y.Funase, M.Suzuno, K.Toko, K.O.Hara, N.Usami, N.Saito, N.Yoshizawa, T.Suemasu

Journal of Crystal Growth   378 巻   頁： 365-367   2013年9月

Enhancement of light emission from Ge quantum dots by photonic crystal nanocavities at room-temperature

XJ.Xu, N.Usami, T.Maruizumi, Y.Shiraki

JOURNAL OF CRYSTAL GROWTH   378 巻   頁： 636-639   2013年9月

On the origin of the uniaxial strain induced in Si/Ge heterostructures with selective ion implantation technique

K.Sawano, Y.Hoshi, S.Nagakura, K.Arimoto, K.Nakagawa, N.Usami, Y.Shiraki

JOURNAL OF CRYSTAL GROWTH   378 巻   頁： 251-253   2013年9月

Molecular beam epitaxy of boron doped p-type BaSi₂ epitaxial films on Si(111) substrates for thin-film solar cells

M.A.Khan, K.O.Hara, K.Nakamura, W.J.Du, M.Baba, K.Toh, M.Suzuno, K.Toko, N.Usami, T.Suemasu

JOURNAL OF CRYSTAL GROWTH   378 巻   頁： 201-204   2013年9月

Large photoresponsivity in semiconducting BaSi₂ epitaxial films grown on Si(001) substrates by molecular beam epitaxy

S.Koike, K.Toh, M.Baba, K.Toko, K.O.Hara, N.Usami, N.Saito, N.Yoshizawa, T.Suemasu

JOURNAL OF CRYSTAL GROWTH   378 巻   頁： 198-200   2013年9月

Gas-source MBE growth of strain-relaxed Si₁-xCx on Si(100) substrates

K.Arimoto, S.Sakai, H.Furukawa, J.Yamanaka, K.Nakagawa, N.Usami, Y.Hoshi, K.Sawano, Y.Shiraki

JOURNAL OF CRYSTAL GROWTH   378 巻   頁： 212-217   2013年9月

Formation of large-grain-sized BaSi₂ epitaxial layers grown on Si(111) by molecular beam epitaxy

M.Baba, K.Toh, K.Toko, K.O.Hara, N.Usami, N.Saito, N.Yoshizawa, T.Suemasu

JOURNAL OF CRYSTAL GROWTH   378 巻   頁： 193-197   2013年9月

Large-Grained Polycrystalline (111) Ge Films on Insulators by Thickness-Controlled Al-Induced Crystallization

K. Nakazawa, K. Toko, N. Saitoh, N.Usami and T. Suemasu

Ecs Journal of Solid State Science and Technology   2 巻 ( 11 ) 頁： Q195-Q199   2013年8月

Control of Dip Shape in Photonic Nanostructures by Maskless Wet-Etching Process and Its Impact on Optical Properties

Y.Hoshi, WG.Pan, T.Kiguchi, K.Ooi, T.Tayagaki, N.Usami

JAPANESE JOURNAL OF APPLIED PHYSICS   52 巻 ( 8 ) 頁： UNSP 080202   2013年8月

Double-Layered Ge Thin Films on Insulators Formed by an Al-Induced Layer-Exchange Process

K.Toko, K.Nakazawa, N.Saitoh, N.Yoshizawa, N.Usami, T.Suemasu

Crystal Growth & Design   13 巻 ( 9 ) 頁： 3908-3912   2013年7月

Temperature dependent Al-induced crystallization of amorphous Ge thin films on SiO2 substrates

K.Toko, N.Fukata, K.Nakazawa, M.Kurosawa, N.Usami, M.Miyao, T.Suemasu

JOURNAL OF CRYSTAL GROWTH   372 巻   頁： 189-192   2013年6月

Effect of Ga content and growth temperature on Cu(In,Ga)Se₂ thin film deposited on heat-resistant glass substrates

T.Higuchi, N.Usami, T.Minemoto

Phys.Status Solidi C   10 巻   頁： 1035-1037   2013年5月

Generation of high photocurrent in three-dimensional silicon quantum dot superlattice fabricated by combining bio-template and neutral beam etching for quantum dot solar cells

M.Igarashi, WG.Hu, M.M.Rahman, N.Usami, S.Samukawa

NANOSCALE RESEARCH LETTERS   8 巻   頁： 228   2013年5月

Structural study on phosphorus doping of BaSi2 epitaxial films by ion implantation

K.O.Hara, Y.Hoshi, N.Usami, Y.Shiraki, K.Nakamura, K.Toko, T.Suemasu,

THIN SOLID FILMS   534 巻   頁： 470-473   2013年5月

Effects of crystal defects and their interactions with impurities on electrical properties of multicrystalline Si

S.Joonwichien, S.Matsushima, N.Usami

JOURNAL OF APPLIED PHYSICS   113 巻 ( 13 ) 頁： 133503   2013年4月

Orientation Control of Large-Grained Si Films on Insulators by Thickness-Modulated Al-Induced Crystallization

R.Numata, K.Toko, N.Saitoh, N.Yoshizawa, N.Usami, T.Suemasu

CRYSTAL GROWTH & DESIGN   13 巻 ( 4 ) 頁： 1767-1770   2013年4月

In-situ heavily p-type doping of over 10(20) cm(-3) in semiconducting BaSi2 thin films for solar cells applications

M.A.Khan, K.O.Hara, W.Du, M.Baba, K.Nakamura, M.Suzuno, K.Toko, N.Usami, T.Suemasu

APPLIED PHYSICS LETTERS   102 巻 ( 11 ) 頁： 112107   2013年3月

Lattice and grain-boundary diffusions of boron atoms in BaSi2 epitaxial films on Si(111)

K. Nakamura, M. Baba, M. A. Khan, W. Du, M. Sasase, K. O. Hara, N. Usami, K. Toko and T. Suemasu

Journal of Applied Physics   113 巻 ( 5 )   2013年2月

Control of Grain Boundary Propagation in Mono-Like Si: Utilization of Functional Grain Boundaries

K. Kutsukake, N. Usami, Y. Ohno, Y. Tokumoto and I. Yonenaga

Applied Physics Express   6 巻 ( 2 )   2013年2月

On the growth mechanism of polycrystalline silicon thin film by Al-induced layer exchange process

N. Usami, M. N. Jung and T. Suemasu

Journal of Crystal Growth   362 巻   頁： 16-19   2013年1月

Effects of formation of mini-bands in two-dimensional array of silicon nanodisks with SiC interlayer for quantum dot solar cells

M. Igarashi, M. F. Budiman, W. G. Pan, W. G. Hu, Y. Tamura, M. E. Syazwan, N. Usami and S. Samukawa

Nanotechnology   24 巻 ( 1 )   2013年1月

Formation of compressively strained Si/S1-xCx/Si(100) heterostructures using gas-source molecular beam epitaxy

K. Arimoto, H. Furukawa, J. Yamanaka, C. Yamamoto, K. Nakagawa, N. Usami, K. Sawano and Y. Shiraki

Journal of Crystal Growth   362 巻   頁： 276-281   2013年1月

Reflectance anisotropies of compressively strained Si grown on vicinal Si1-xCx(001)

R. E. Balderas-Navarro, N. A. Ulloa-Castillo, K. Arimoto, G. Ramirez-Melendez, L. F. Lastras-Martinez, H. Furukawa, J. Yamanaka, A. Lastras-Martinez, J. M. Flores-Camacho, N. Usami, D. Stifter and K. Hingerl

Applied Physics Letters   102 巻 ( 1 )   2013年1月

Evaluation of potential variations around grain boundaries in BaSi2 epitaxial films by Kelvin probe force microscopy

M.Baba, S.Tsurekawa, K.Watanabe, W.Du, K.Toko, K.O.Hara, N.Usami, T.Sekiguchi and T.Suemasu

Applied Physics Letters   103 巻   頁： 142113   2013年

Theory of open-circuit voltage and the driving force of charge separation in pn-junction solar cells

K.O. Hara, N.Usami

Journal of Applied Physics   114 巻 ( 15 ) 頁： 153101   2013年

Silicon-Based Light-Emitting Devices Based on Ge Self-Assembled Quantum Dots Embedded in Optical Cavities

X. J. Xu, S. Narusawa, T. Chiba, T. Tsuboi, J. S. Xia, N. Usami, T. Maruizumi and Y. Shiraki

Ieee Journal of Selected Topics in Quantum Electronics   18 巻 ( 6 ) 頁： 1830-1838   2012年12月

Influence of Thermal Annealing on the Carrier Extraction in Ge/Si Quantum Dot Solar Cells

T. Tayagaki, N. Usami and Y. Kanemitsu

Japanese Journal of Applied Physics   51 巻 ( 10 )   2012年10月

Dependence of crystal orientation in Al-induced crystallized poly-Si layers on SiO2 insertion layer thickness

A. Okada, K. Toko, K. O. Hara, N. Usami and T. Suemasu

Journal of Crystal Growth   356 巻   頁： 65-69   2012年10月

Large-Grain Polycrystalline Silicon Films Formed through Flash-Lamp-Induced Explosive Crystallization

K. Ohdaira, K. Sawada, N. Usami, S. Varlamov and H. Matsumura

Japanese Journal of Applied Physics   51 巻 ( 10 )   2012年10月

Realization of Large-Domain Barium Disilicide Epitaxial Thin Film by Introduction of Miscut to Si(111) Substrate

K. O. Hara, N. Usami, K. Toh, K. Toko and T. Suemasu

Japanese Journal of Applied Physics   51 巻 ( 10 )   2012年10月

Growth velocity and grain size of multicrystalline solar cell silicon

I. Brynjulfsen, K. Fujiwara, N. Usami and L. Amberg

Journal of Crystal Growth   356 巻   頁： 17-21   2012年10月

Investigation of the recombination mechanism of excess carriers in undoped BaSi2 films on silicon

K. O. Hara, N. Usami, K. Toh, M. Baba, K. Toko and T. Suemasu

Journal of Applied Physics   112 巻 ( 8 )   2012年10月

Epitaxy of Orthorhombic BaSi2 with Preferential In-Plane Crystal Orientation on Si(001): Effects of Vicinal Substrate and Annealing Temperature

K. Toh, K. O. Hara, N. Usami, N. Saito, N. Yoshizawa, K. Toko and T. Suemasu

Japanese Journal of Applied Physics   51 巻 ( 9 )   2012年9月

Enhanced carrier extraction from Ge quantum dots in Si solar cells under strong photoexcitation

T. Tayagaki, N. Usami, W. G. Pan, Y. Hoshi, K. Ooi and Y. Kanemitsu

Applied Physics Letters   101 巻 ( 13 )   2012年9月

Molecular Beam Epitaxy of BaSi2 Films with Grain Size over 4 mu m on Si(111)

M. Baba, K. Nakamura, W. J. Du, M. A. Khan, S. Koike, K. Toko, N. Usami, N. Saito, N. Yoshizawa and T. Suemasu

Japanese Journal of Applied Physics   51 巻 ( 9 )   2012年9月

Highly (111)-oriented Ge thin films on insulators formed by Al-induced crystallization

K. Toko, M. Kurosawa, N. Saitoh, N. Yoshizawa, N. Usami, M. Miyao and T. Suemasu

Applied Physics Letters   101 巻 ( 7 )   2012年8月

Quantum dot solar cells using 2-dimensional array of 6.4-nm-diameter silicon nanodisks fabricated using bio-templates and neutral beam etching

M. Igarashi, M. F. Budiman, W. G. Pan, W. G. Hu, N. Usami and S. Samukawa

Applied Physics Letters   101 巻 ( 6 )   2012年8月

Silicon-based current-injected light emitting diodes with Ge self-assembled quantum dots embedded in photonic crystal nanocavities

X. J. Xu, T. Tsuboi, T. Chiba, N. Usami, T. Maruizumi and Y. Shiraki

Optics Express   20 巻 ( 13 ) 頁： 14714-14721   2012年6月

Investigation of grain boundaries in BaSi2 epitaxial films on Si(111) substrates using transmission electron microscopy and electron-beam-induced current technique

M. Baba, K. Toh, K. Toko, N. Saito, N. Yoshizawa, K. Jiptner, T. Sekiguchi, K. O. Hara, N. Usami and T. Suemasu

Journal of Crystal Growth   348 巻 ( 1 ) 頁： 75-79   2012年6月

Simultaneous enhanced photon capture and carrier generation in Si solar cells using Ge quantum dot photonic nanocrystals

N. Usami, W. G. Pan, T. Tayagaki, S. T. Chu, J. S. Li, T. H. Feng, Y. Hoshi and T. Kiguchi

Nanotechnology   23 巻 ( 18 )   2012年5月

Room-Temperature Electroluminescence from Ge Quantum Dots Embedded in Photonic Crystal Microcavities

T. Tsuboi, X. J. Xu, J. S. Xia, N. Usami, T. Maruizumi and Y. Shiraki

Applied Physics Express   5 巻 ( 5 )   2012年5月

Upper limit of two-dimensional hole gas mobility in strained Ge/SiGe heterostructures

T. Tanaka, Y. Hoshi, K. Sawano, N. Usami, Y. Shiraki and K. M. Itoh

Applied Physics Letters   100 巻 ( 22 )   2012年5月

Molecular beam epitaxy of BaSi2 thin films on Si(001) substrates

K. Toh, K. O. Hara, N. Usami, N. Saito, N. Yoshizawa, K. Toko and T. Suemasu

Journal of Crystal Growth   345 巻 ( 1 ) 頁： 16-21   2012年4月

Growth of multicrystalline Si ingots using noncontact crucible method for reduction of stress

K. Nakajima, R. Murai, K. Morishita, K. Kutsukake and N. Usami

Journal of Crystal Growth   344 巻 ( 1 )   2012年4月

Effect of Phase Purity on Dislocation Density of Pressurized-Reactor Metalorganic Vapor Phase Epitaxy Grown InN

T. Iwabuchi, Y. H. Liu, T. Kimura, Y. T. Zhang, K. Prasertsuk, H. Watanabe, N. Usami, R. Katayama and T. Matsuoka

Japanese Journal of Applied Physics   51 巻 ( 4 )   2012年4月

Effect of Solid-Phase-Epitaxy Si Layers on Suppression of Sb Diffusion from Sb-Doped n(+)-BaSi2/p(+)-Si Tunnel Junction to Undoped BaSi2 Overlayers

W. J. Du, T. Saito, M. A. Khan, K. Toko, N. Usami and T. Suemasu

Japanese Journal of Applied Physics   51 巻 ( 4 )   2012年4月

Improved photoresponsivity of semiconducting BaSi2 epitaxial films grown on a tunnel junction for thin-film solar cells

W. J. Du, M. Suzuno, M. A. Khan, K. Toh, M. Baba, K. Nakamura, K. Toko, N. Usami and T. Suemasu

Applied Physics Letters   100 巻 ( 15 )   2012年4月

Structural Study of BF2 Ion Implantation and Post Annealing of BaSi2 Epitaxial Films

K. O. Hara, N. Usami, Y. Hoshi, Y. Shiraki, M. Suzuno, K. Toko and T. Suemasu

Japanese Journal of Applied Physics   50 巻 ( 12 )   2011年12月

The effect of the presence of an Al-doped ZnO layer on the preferential crystal orientation of polycrystalline silicon thin films grown by an Al-induced layer exchange method

M. Jung, A. Okada, T. Saito, T. Suemasu and N. Usami

Journal of Ceramic Processing Research   12 巻   頁： S187-S192   2011年11月

Generation mechanism of dislocations and their clusters in multicrystalline silicon during two-dimensional growth

K. Kutsukake, T. Abe, N. Usami, K. Fujiwara, I. Yonenaga, K. Morishita and K. Nakajima

Journal of Applied Physics   110 巻 ( 8 )   2011年10月

Formation mechanism of twin boundaries during crystal growth of silicon

K. Kutsukake, T. Abe, N. Usami, K. Fujiwara, K. Morishita and K. Nakajima

Scripta Materialia   65 巻 ( 6 ) 頁： 556-559   2011年9月

Line Width Dependence of Anisotropic Strain State in SiGe Films Induced by Selective Ion Implantation

Y. Hoshi, K. Sawano, A. Yamada, S. Nagakura, N. Usami, K. Arimoto, K. Nakagawa and Y. Shiraki

Applied Physics Express   4 巻 ( 9 )   2011年9月

Configuration and local elastic interaction of ferroelectric domains and misfit dislocation in PbTiO3/SrTiO3 epitaxial thin films

T. Kiguchi, K. Aoyagi, Y. Ehara, H. Funakubo, T. Yamada, N. Usami and T. J. Konno

Science and Technology of Advanced Materials   12 巻 ( 3 )   2011年6月

Implementation of faceted dendrite growth on floating cast method to realize high-quality multicrsytalline Si ingot for solar cells

N. Usami, I. Takahashi, K. Kutsukake, K. Fujiwara and K. Nakajima

Journal of Applied Physics   109 巻 ( 8 )   2011年4月

Effects of increased compressive strain on hole effective mass and scattering mechanisms in strained Ge channels

K. Sawano, K. Toyama, R. Masutomi, T. Okamoto, K. Arimoto, K. Nakagawa, N. Usami and Y. Shiraki

Microelectronic Engineering   88 巻   頁： 465-468   2011年4月

In situ Observation of Polycrystalline Silicon Thin Films Grown Using Aluminum-Doped Zinc Oxide on Glass Substrate by the Aluminum-Induced Crystallization

M. Jung, A. Okada, T. Saito, T. Suemasu, C. Y. Chung, Y. Kawazoe and N. Usami

Japanese Journal of Applied Physics   50 巻 ( 4 )   2011年4月

Impact of type of crystal defects in multicrystalline Si on electrical properties and interaction with impurities

I. Takahashi, N. Usami, H. Mizuseki, Y. Kawazoe, G. Stokkan and K. Nakajima

Journal of Applied Physics   109 巻 ( 3 )   2011年2月

Pattern formation mechanism of a periodically faceted interface during crystallization of Si

M. Tokairin, K. Fujiwara, K. Kutsukake, H. Kodama, N. Usami and K. Nakajima

Journal of Crystal Growth   312 巻 ( 24 ) 頁： 3670-3674   2010年12月

A grazing incidence small-angle x-ray scattering analysis on capped Ge nanodots in layer structures

H. Okuda, M. Kato, K. Kuno, S. Ochiai, N. Usami, K. Nakajima and O. Sakata

Journal of Physics-Condensed Matter   22 巻 ( 47 )   2010年12月

Impact of amorphous Ge thin layer at the amorphous Si/Al interface on Al-induced crystallization

H. Suzuki, N. Usami, A. Nomura, T. Shishido, K. Nakajima and T. Suemasu

Journal of Crystal Growth   312 巻 ( 22 ) 頁： 3257-3260   2010年11月

Direct bandgap measurements in a three-dimensionally macroporous silicon 9R polytype using monochromated transmission electron microscope

L. Gu, Y. Yu, W. Sigle, N. Usami, S. Tsukimoto, J. Maier, Y. Ikuhara and P. A. van Aken

Applied Physics Letters   97 巻 ( 21 )   2010年11月

Room-temperature electroluminescence from Si microdisks with Ge quantum dots

J. S. Xia, Y. Takeda, N. Usami, T. Maruizumi and Y. Shiraki

Optics Express   18 巻 ( 13 ) 頁： 13945-13950   2010年6月

Growth mechanism of the Si < 110 > faceted dendrite

K. Fujiwara, H. Fukuda, N. Usami, K. Nakajima and S. Uda

Physical Review B   81 巻 ( 22 )   2010年6月

Generation mechanism of dislocations during directional solidification of multicrystalline silicon using artificially designed seed

I. Takahashi, N. Usami, K. Kutsukake, G. Stokkan, K. Morishita and K. Nakajima

Journal of Crystal Growth   312 巻 ( 7 ) 頁： 897-901   2010年3月

Ion dose, energy, and species dependencies of strain relaxation of SiGe buffer layers fabricated by ion implantation technique

Y. Hoshi, K. Sawano, A. Yamada, N. Usami, K. Arimoto, K. Nakagawa and Y. Shiraki

Journal of Applied Physics   107 巻 ( 10 )   2010年3月

Optical anisotropies of Si grown on step-graded SiGe(110) layers

R. E. Balderas-Navarro, L. F. Lastras-Martinez, K. Arimoto, R. Castro-Garcia, O. Villalobos-Aguilar, A. Lastras-Martinez, K. Nakagawa, K. Sawano, Y. Shiraki, N. Usami and K. Nakajima

Applied Physics Letters   96 巻 ( 9 )   2010年3月

Formation of uniaxially strained SiGe by selective ion implantation technique

K. Sawano, Y. Hoshi, A. Yamada, Y. Hiraoka, N. Usami, K. Arimoto, K. Nakagawa and Y. Shiraki

Thin Solid Films   518 巻 ( 9 ) 頁： 2454-2457   2010年2月

Relationship between grain boundary structures in Si multicrystals and generation of dislocations during crystal growth

N. Usami, R. Yokoyama, I. Takahashi, K. Kutsukake, K. Fujiwara and K. Nakajima

Journal of Applied Physics   107 巻 ( 1 )   2010年1月

Ion energy and dose dependence of strain relaxation for thin SiGe buffer layers using Si+ implantation

Y. Hoshi, K. Sawano, A. Yamada, K. Arimoto, N. Usami, K. Nakagawa and Y. Shiraki

Thin Solid Films   518 巻   頁： S162-S164   2010年1月

Computational Investigation of Relationship between Shear Stress and Multicrystalline Structure in Silicon

I. Takahashi, N. Usami, K. Kutsukake, K. Morishita and K. Nakajima

Japanese Journal of Applied Physics   49 巻 ( 4 )   2010年

Fabrication of n(+)-BaSi2/p(+)-Si Tunnel Junction on Si(111) Surface by Molecular Beam Epitaxy for Photovoltaic Applications

T. Saito, Y. Matsumoto, M. Suzuno, M. Takeishi, R. Sasaki, T. Suemasu and N. Usami

Applied Physics Express   3 巻 ( 2 )   2010年

Lattice-Latching Effect in Metalorganic Vapor Phase Epitaxy Growth of InGaAsN Film Lattice-Matched to Bulk InGaAs Substrate

S. Sanorpim, R. Katayama, K. Onabe, N. Usami and K. Nakajima

Japanese Journal of Applied Physics   49 巻 ( 4 )   2010年

Epitaxial Growth and Photoresponse Properties of BaSi2 Layers toward Si-Based High-Efficiency Solar Cells

Y. Matsumoto, D. Tsukada, R. Sasaki, M. Takeishi, T. Saito, T. Suemasu, N. Usami and M. Sasase

Japanese Journal of Applied Physics   49 巻   2010年

On the Controlling Mechanism of Preferential Orientation of Polycrystalline-Silicon Thin Films Grown by Aluminum-Induced Crystallization

M. Jung, A. Okada, T. Saito, T. Suemasu and N. Usami

Applied Physics Express   3 巻 ( 9 )   2010年

Growth behavior of faceted Si crystals at grain boundary formation

K. Fujiwara, S. Tsumura, M. Tokairin, K. Kutsukake, N. Usami, S. Uda and K. Nakajima

Journal of Crystal Growth   312 巻 ( 1 ) 頁： 19-23   2009年12月

Formation mechanism of a faceted interface: In situ observation of the Si(100) crystal-melt interface during crystal growth

M. Tokairin, K. Fujiwara, K. Kutsukake, N. Usami and K. Nakajima

Physical Review B   80 巻 ( 17 )   2009年11月

Growth of Compositionally Graded SiGe Bulk Crystal and Its Application As Substrate with Lateral Variation in Ge Content

R. Nihei, N. Usami and K. Nakajima

Japanese Journal of Applied Physics   48 巻 ( 11 )   2009年11月

Strain relaxation mechanisms in compositionally uniform and step-graded SiGe films grown on Si(110) substrates

K. Arimoto, M. Watanabe, J. Yamanaka, K. Nakagawa, K. Sawano, Y. Shiraki, N. Usami and K. Nakajima

Solid-State Electronics   53 巻 ( 10 ) 頁： 1135-1143   2009年10月

Strain dependence of hole effective mass and scattering mechanism in strained Ge channel structures

K. Sawano, K. Toyama, R. Masutomi, T. Okamoto, N. Usami, K. Arimoto, K. Nakagawa and Y. Shiraki

Applied Physics Letters   95 巻   2009年9月

Fabrication of (111)-oriented Si layers on SiO2 substrates by an aluminum-induced crystallization method and subsequent growth of semiconducting BaSi2 layers for photovoltaic application

D. Tsukada, Y. Matsumoto, R. Sasaki, M. Takeishi, T. Saito, N. Usami and T. Suemasu

Journal of Crystal Growth   311 巻 ( 14 ) 頁： 3581-3586   2009年7月

Microstructures of Si multicrystals and their impact on minority carrier diffusion length

H. Y. Wang, N. Usami, K. Fujiwara, K. Kutsukake and K. Nakajima

Acta Materialia   57 巻 ( 11 ) 頁： 3268-3276   2009年6月

Photoresponse Properties of Polycrystalline BaSi2 Films Grown on SiO2 Substrates Using (111)-Oriented Si Layers by an Aluminum-Induced Crystallization Method

D. Tsukada, Y. Matsumoto, R. Sasaki, M. Takeishi, T. Saito, N. Usami and T. Suemasu

Applied Physics Express   2 巻 ( 5 )   2009年5月

Generation and Wavelength Control of Resonant Luminescence from Silicon Photonic Crystal Microcavities with Ge Dots

J. Xia, R. Tominaga, S. Fukamitsu, N. Usami and Y. Shiraki

Japanese Journal of Applied Physics   48 巻 ( 2 )   2009年2月

Quantitative analysis of subgrain boundaries in Si multicrystals and their impact on electrical properties and solar cell performance

K. Kutsukake, N. Usami, T. Ohtaniuchi, K. Fujiwara and K. Nakajima

Journal of Applied Physics   105 巻 ( 4 )   2009年2月

Floating cast method to realize high-quality Si bulk multicrystals for solar cells

Y. Nose, I. Takahashi, W. Pan, N. Usami, K. Fujiwara and K. Nakajima

Journal of Crystal Growth   311 巻 ( 2 ) 頁： 228-231   2009年1月

Resonant photoluminescence from Ge self-assembled dots in optical microcavities

J. S. Xia, R. Tominaga, N. Usami, S. Iwamoto, Y. Ikegami, K. Nemoto, Y. Arakawa and Y. Shiraki

JOURNAL OF CRYSTAL GROWTH   311 巻   頁： 883-887   2009年

Local control of strain in SiGe by ion-implantation technique

K. Sawano, Y. Hoshi, Y. Hiraoka, N. Usami, K. Nakagawa and Y. Shiraki

JOURNAL OF CRYSTAL GROWTH   311 巻 ( 3 ) 頁： 806-808   2009年

Fabrication of thin strain-relaxed SiGe buffer layers with high Ge composition by ion implantation method

Y. Hoshi, K. Sawano, Y. Hiraoka, Y. Sato, Y. Ogawa, A. Yamada, N. Usami, K. Nakagawa and Y. Shiraki

JOURNAL OF CRYSTAL GROWTH   311 巻 ( 3 ) 頁： 825-828   2009年

Strain relaxation mechanisms in step-graded SiGe/Si(110) heterostructures grown by gas-source MBE at high temperatures

K. Arimoto, M. Watanabe, J. Yamanaka, K. Nakagawa, N. Usami, K. Nakajima, K. Sawano and Y. Shiraki

J. Cryst. Growth   311 巻   頁： 819-824   2009年

Crystalline morphologies of step-graded SiGe layers grown on exact and vicinal (110) Si substrates

K. Arimoto, M. Watanabe, J. Yamanaka, K. Nakagawa, K. Sawano, Y. Shiraki, N. Usami and K. Nakajima

J. Cryst. Growth   311 巻   頁： 809-813   2009年

Structural and transport properties of strained SiGe grown on V-groove patterned Si(110) substrates

K. Arimoto, G. Kawaguchi, K. Shimizu, M. Watanabe, J. Yamanaka, K. Nakagawa, N. Usami, K. Nakajima, K. Sawano and Y. Shiraki

J. Cryst. Growth   311 巻   頁： 814-818   2009年

Influence of growth temperature and cooling rate on the growth of Si epitaxial layer by dropping-type liquid phase epitaxy from the pure Si melt

Z. M. Wang, K. Kutsukake, H. Kodama, N. Usami, K. Fujiwara, Y. Nose and K. Nakajima

Journal of Crystal Growth   310 巻 ( 24 ) 頁： 5248-5251   2008年12月

Impact of Defect Density in Si Bulk Multicrystals on Gettering Effect of Impurities

I. Takahashi, N. Usami, R. Yokoyama, Y. Nose, K. Kutuskake, K. Fuilwara and K. Nakajima

Japanese Journal of Applied Physics   47 巻 ( 12 ) 頁： 8790-8792   2008年12月

Introduction of Uniaxial Strain into Si/Ge Heterostructures by Selective Ion Implantation

K. Sawano, Y. Hoshi, A. Yamada, Y. Hiraoka, N. Usami, K. Arimoto, K. Nakagawa and Y. Shiraki

Applied Physics Express   1 巻 ( 12 )   2008年12月

Room-temperature light-emission from Ge quantum dots in photonic crystals

J. Xia, K. Nemoto, Y. Ikegami, N. Usami, Y. Nakata and Y. Shiraki

Thin Solid Films   517 巻 ( 1 ) 頁： 125-127   2008年11月

Application of SiGe bulk crystal as a substrate for strain-controlled heterostructure materials

N. Usami, R. Nihei, Y. Azuma, I. Yonenaga, K. Nakajima, K. Sawano and Y. Shiraki

Thin Solid Films   517 巻 ( 1 ) 頁： 14-16   2008年11月

Characterizations of polycrystalline SiGe films on SiO2 grown by gas-source molecular beam deposition

M. Mitsui, M. Tamoto, K. Arimoto, J. Yamanaka, K. Nakagawa, T. Sato, N. Usami, K. Sawano and Y. Shiraki

Thin Solid Films   517 巻 ( 1 ) 頁： 254-256   2008年11月

Growth temperature dependence of the crystalline morphology of SiGe films grown on Si(110) substrates with compositionally step-graded buffer

K. Arimoto, M. Watanabe, J. Yamanaka, K. Nakagawa, K. Sawano, Y. Shiraki, N. Usami and K. Nakajima

Thin Solid Films   517 巻 ( 1 ) 頁： 235-238   2008年11月

Vacancy formation during oxidation of silicon crystal surface

M. Suezawa, Y. Yamamoto, M. Suemitsu, N. Usami and I. Yonenaga

Applied Physics Letters   93 巻 ( 10 )   2008年9月

Development of thin SiGe relaxed layers with high-Ge composition by ion implantation method and application to strained Ge channels

Y. Hoshi, K. Sawano, Y. Hiraoka, Y. Satoh, Y. Ogawa, A. Yamada, N. Usami, K. Nakagawa and Y. Shiraki

Applied Physics Express   1 巻 ( 8 )   2008年8月

Growth mechanism of Si-faceted dendrites

K. Fujiwara, K. Maeda, N. Usami and K. Nakajima

Physical Review Letters   101 巻 ( 5 )   2008年8月

Structural origin of a cluster of bright spots in reverse bias electroluminescence image of solar cells based on Si multicrystals

N. Usami, K. Kutsukake, K. Fujiwara, I. Yonenaga and K. Nakajima

Applied Physics Express   1 巻 ( 7 )   2008年7月

Acceptorlike behavior of defects in SiGe alloys grown by molecular beam epitaxy

M. Satoh, K. Arimoto, K. Nakagawa, S. Koh, K. Sawano, Y. Shiraki, N. Usami and K. Nakajima

Japanese Journal of Applied Physics   47 巻 ( 6 ) 頁： 4630-4633   2008年6月

In situ observation of Si faceted dendrite growth from low-degree-of-undercooling melts

K. Fujiwara, K. Maeda, N. Usami, G. Sazaki, Y. Nose, A. Nomura, T. Shishido and K. Nakajima

Acta Materialia   56 巻 ( 11 ) 頁： 2663-2668   2008年6月

On effects of gate bias on hole effective mass and mobility in strained-Ge channel structures

K. Sawano, Y. Kunishi, Y. Satoh, K. Toyama, K. Arimoto, T. Okamoto, N. Usami, K. Nakagawa and Y. Shiraki

Applied Physics Express   1 巻 ( 1 )   2008年1月

Hole density and strain dependencies of hole effective mass in compressively strained Ge channel structures

K. Sawano, Y. Kunishi, K. Toyama, T. Okamoto, N. Usami, K. Nakagawa and Y. Shiraki

PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES   40 巻 ( 6 ) 頁： 2122-2124   2008年

Poly-Si films with long carrier lifetime prepared by rapid thermal annealing of Cat-CVD amorphous silicon thin films

K. Ohdaira, Y. Abe, M. Fukuda, S. Nishizaki, N. Usami, K. Nakajima, T. Karasawa, T. Torikai and H. Matsumura

THIN SOLID FILMS   516 巻 ( 5 ) 頁： 600-603   2008年

Functional enhancement of metal-semiconductor-metal infrared photodetectors on heteroepitaxial SiGe-on-Si using the anodic oxidation/passivation method

R. W. Chuang, Z. L. Liao, H. T. Chiang and N. Usami

Jpn. J. Appl. Phys.   47 巻   頁： 2927-2931   2008年

Modification of local structures in multicrystals revealed by spatially resolved x-ray rocking curve analysis

N. Usami, K. Kutsukake, K. Fujiwara and K. Nakajima

Journal of Applied Physics   102 巻 ( 10 )   2007年11月

High-quality polycrystalline silicon films with minority carrier lifetimes over 5 mu s formed by flash lamp annealing of precursor amorphous silicon films prepared by catalytic chemical vapor deposition

K. Ohdaira, S. Nishizaki, Y. Endo, T. Fujiwara, N. Usami, K. Nakajima and H. Matsumura

Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers   46 巻 ( 11 ) 頁： 7198-7203   2007年11月

Silicon-based light emitters fabricated by embedding Ge self-assembled quantum dots in microdisks

J. S. Xia, K. Nemoto, Y. Ikegami, Y. Shiraki and N. Usami

Applied Physics Letters   91 巻 ( 1 )   2007年7月

SiGe double barrier resonant tunneling diodes on bulk SiGe substrates with high peak-to-valley current ratio

S. Tsujino, N. Usami, A. Weber, G. Mussler, V. Shushunova, D. Grutzmacher, Y. Azuma and K. Nakajima

Applied Physics Letters   91 巻   2007年7月

Formation mechanism of parallel twins related to Si-facetted dendrite growth

K. Fujiwara, K. Maeda, N. Usami, G. Sazaki, Y. Nose and K. Nakajima

Scripta Materialia   57 巻 ( 2 ) 頁： 81-84   2007年7月

Application of Czochralski-grown SiGe bulk crystal as a substrate for luminescent strained quantum wells

N. Usami, R. Nihei, I. Yonenaga, Y. Nose and K. Nakajima

Applied Physics Letters   90 巻 ( 18 )   2007年4月

Improvement in the conversion efficiency of single-junction SiGe solar cells by intentional introduction of the compositional distribution

M. Tayanagi, N. Usami, W. Pan, K. Ohdaira, K. Fujiwara, Y. Nose and K. Nakajima

Journal of Applied Physics   101 巻 ( 5 )   2007年3月

Influence of structural imperfection of Sigma 5 grain boundaries in bulk multicrystalline Si on their electrical activities

K. Kutsukake, N. Usami, K. Fujiwara, Y. Nose and K. Nakajima

Journal of Applied Physics   101 巻 ( 6 )   2007年3月

Step-induced anisotropic growth of pentacene thin film crystals on a hydrogen-terminated Si(111) surface

S. Nishikata, G. Sazaki, T. Takeuchi, N. Usami, S. Suto and K. Nakajima

Crystal Growth & Design   7 巻 ( 2 ) 頁： 439-444   2007年2月

Modification of local structure and its influence on electrical activity of near (310) Sigma 5 grain boundary in bulk silicon

K. Kutsukake, N. Usami, K. Fujiwara, Y. Nose, T. Sugawara, T. Shishido and K. Nakajima

Materials Transactions   48 巻 ( 2 ) 頁： 143-147   2007年2月

Effect of the compositional distribution on the photovoltaic power conversion of SiGe solar cells

N. Usami, W. Pan, K. Fujiwara, M. Tayanagi, K. Ohdaira and K. Nakajima

Solar Energy Materials and Solar Cells   91 巻   頁： 123-128   2007年1月

Control of strain status in SiGe thin film by epitaxial growth on Si with buried porous layer

N. Usami, K. Kutsukake, N. Kazuo, S. Amtablian, A. Fave and M. Lemiti

Applied Physics Letters   90 巻 ( 3 )   2007年1月

Fabrication of Ge channels with extremely high compressive strain and their magnetotransport properties

K. Sawano, Y. Kunishi, K. Toyama, T. Okamoto, N. Usami, K. Nakagawa and Y. Shiraki

JOURNAL OF CRYSTAL GROWTH   301 巻   頁： 339-342   2007年

Growth temperature dependence of lattice structures of SiGe/graded buffer structures grown on Si(110) substrates by gas-source MBE

K. Arimoto, J. Yamanaka, K. Nakagawa, K. Sawano, Y. Shiraki, N. Usami and K. Nakajima

J. Cryst. Growth   301 巻   頁： 343-348   2007年

Annihilation of acceptor-hydrogen pairs in Si crystals due to electron irradiation

M. Suezawa, K. Koilma, A. Kasuya, I. Yonenaga and N. Usami

Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers   45 巻 ( 12 ) 頁： 9162-9166   2006年12月

Strong resonant luminescence from Ge quantum dots in photonic crystal microcavity at room temperature

J. S. Xia, Y. Ikegami, Y. Shiraki, N. Usami and Y. Nakata

Applied Physics Letters   89 巻 ( 20 )   2006年11月

Magnetotransport properties of Ge channels with extremely high compressive strain

K. Sawano, Y. Kunishi, Y. Shiraki, K. Toyama, T. Okamoto, N. Usami and K. Nakagawa

Applied Physics Letters   89 巻 ( 16 )   2006年10月

Growth of structure-controlled polycrystalline silicon ingots for solar cells by casting

K. Fujiwara, W. Pan, N. Usami, K. Sawada, M. Tokairin, Y. Nose, A. Nomura, T. Shishido and K. Nakajima

Acta Materialia   54 巻 ( 12 ) 頁： 3191-3197   2006年7月

High sensitive imaging of atomic arrangement of Ge clusters buried in a Si crystal by X-ray fluorescence holography

S. Kusano, S. Nakatani, K. Sumitani, T. Takahashi, Y. Yoda, N. Usami and Y. Shiraki

Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers   45 巻 ( 6A ) 頁： 5248-5253   2006年6月

Suppression of structural imperfection in strained Si by utilizing SiGe bulk substrate

N. Usami, Y. Nose, K. Fujiwara and K. Nakajima

Applied Physics Letters   88 巻   2006年5月

Realization of bulk multicrystalline silicon with controlled grain boundaries by utilizing spontaneous modification of grain boundary configuration

N. Usami, K. Kutsukake, T. Sugawara, K. Fujwara, W. Pan, Y. Nose, T. Shishido and K. Nakajima

Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers   45 巻 ( 3A ) 頁： 1734-1737   2006年3月

High-efficiency concave and conventional solar cell integration system using focused reflected light

K. Ohdaira, K. Fujiwara, W. Pan, N. Usami and K. Nakajiima

Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers   45 巻 ( 3A ) 頁： 1664-1667   2006年3月

Intermixing of Ge and Si during exposure of GeH4 on Si

G. Watari, N. Usami, Y. Nose, K. Fujiwara, G. Sazaki and K. Nakajima

THIN SOLID FILMS   508 巻   頁： 163-165   2006年

Strain field and related roughness formation in SiGe relaxed buffer layers

K. Sawano, N. Usami, K. Arimoto, K. Nakagawa and Y. Shiraki

THIN SOLID FILMS   508 巻 ( 1-2 ) 頁： 117-119   2006年

Influence of stacked Ge islands on the dark current-voltage characteristics and the conversion efficiency of the solar cells

A. Alguno, N. Usami, K. Ohdaira, W. G. Pan, M. Tayanagi and K. Nakajima

Thin Solid Films   508 巻   頁： 402-405   2006年

Directional growth method to obtain high quality polycrystalline silicon from its melt

K. Fujiwara, W. Pan, K. Sawada, M. Tokairin, N. Usami, Y. Nose, A. Nomura, T. Shishido and K. Nakajima

J. Cryst. Growth   292 巻   頁： 282-285   2006年

Determination of lattice parameters of SiGe/Si(110) heterostructures

K. Arimoto, J. Yamanaka, K. Nakagawa, K. Sawano, Y. Shiraki, S. Koh and N. Usami

Thin Solid Films   508 巻   頁： 132-135   2006年

Thickness dependence of strain field distribution in SiGe relaxed buffer layers

K. Sawano, N. Usami, K. Arimoto, K. Nakagawa and Y. Shiraki

Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers   44 巻   頁： 8445-8447   2005年12月

Analysis of the dark-current density in solar cells based on multicrystalline SiGe

K. Ohdaira, N. Usami, W. G. Pan, K. Fujiwara and K. Nakajima

Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers   44 巻 ( 11 ) 頁： 8019-8022   2005年11月

Floating zone growth of Si-rich SiGe bulk crystal using pre-synthesized SiGe feed rod with uniform composition

N. Usami, M. Kitamura, K. Obara, Y. Nose, T. Shishido and K. Nakajima

Journal of Crystal Growth   284 巻   頁： 57-64   2005年10月

Influence of growth temperature on minority-carrier lifetime of Si layer grown by liquid phase epitaxy using Ga solvent

Y. Satoh, N. Usami, W. Pan, K. Fujiwara, K. Nakajima and T. Ujihara

Journal of Applied Physics   98 巻 ( 7 )   2005年10月

Changes in elastic deformation of strained si by microfabrication (vol 8, pg 181, 2005)

K. Arimoto, D. Furukawa, J. Yamanaka, K. Nakagawa, K. Sawano, S. Koh, Y. Shiraki and N. Usami

Materials Science in Semiconductor Processing   8 巻 ( 6 ) 頁： 652-652   2005年10月

Liquid phase epitaxial growth of Si layers on Si thin substrates from Si pure melts under near-equilibrium conditions

K. Nakajima, K. Fujiwara, Y. Nose and N. Usami

Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers   44 巻 ( 7A ) 頁： 5092-5095   2005年7月

Growth of multicrystalline Si with controlled grain boundary configuration by the floating zone technique

M. Kitamura, N. Usami, T. Sugawara, K. Kutsukake, K. Fujiwara, Y. Nose, T. Shishido and K. Nakajima

Journal of Crystal Growth   280 巻   頁： 419-424   2005年7月

Crystal quality of a 6H-SiC layer grown over macrodefects by liquid-phase epitaxy: a Raman spectroscopic study

T. Ujihara, S. Munetoh, K. Kusunoki, K. Kamei, N. Usami, K. Fujiwara, G. Sazaki and K. Nakajima

Thin Solid Films   476 巻 ( 1 ) 頁： 206-209   2005年4月

A simple approach to determine preferential growth orientation using multiple seed crystals with random orientations and its utilization for seed optimization to restrain polycrystallization of SiGe bulk crystal

Y. Azuma, N. Usami, K. Fujiwara, T. Ujihara and K. Nakajima

Journal of Crystal Growth   276 巻   頁： 393-400   2005年4月

Structural properties of directionally grown polycrystalline SiGe for solar cells

K. Fujiwara, W. Pan, N. Usami, K. Sawada, A. Nomura, T. Ujihara, T. Shishido and K. Nakajima

Journal of Crystal Growth   275 巻   頁： 467-473   2005年3月

On the origin of improved conversion efficiency of solar cells based on SiGe with compositional distribution

N. Usami, K. Fujiwara, W. G. Pan and K. Nakajima

Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers   44 巻 ( 2 ) 頁： 857-860   2005年2月

Growth of ZnO/MgZnO quantum wells on sapphire substrates and observation of the two-dimensional confinement effect

B. P. Zhang, N. T. Binh, K. Wakatsuki, C. Y. Liu and Y. Segawa and N. Usami

Applied Physics Letters   86 巻 ( 3 )   2005年1月

Effects of vicinal steps on the island growth and orientation of epitaxially grown perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) thin film crystals on a hydrogen-terminated Si(111) substrate

G. Sazaki, T. Fujino, N. Usami, T. Ujihara, K. Fujiwara and K. Nakajima

Journal of Crystal Growth   273 巻   頁： 594-602   2005年1月

Floating zone growth of Si bicrystals using seed crystals with artificially designed grain boundary configuration

N. Usami, M. Kitamura, T. Sugawara, K. Kutsukake, K. Ohdaira, Y. Nose, K. Fujiwara, T. Shishido and K. Nakajima

Japanese Journal of Applied Physics Part 2-Letters & Express Letters   44 巻 ( 24-27 ) 頁： L778-L780   2005年

Observation of strain field fluctuation in SiGe-relaxed buffer layers and its influence on overgrown structures

K. Sawano, N. Usami, K. Arimoto, S. Koh, K. Nakagawa and Y. Shiraki

MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING   8 巻 ( 1-3 ) 頁： 177-180   2005年

Strain-field evaluation of strain-relaxed thin SiGe layers fabricated by ion implantation method

K. Sawano, Y. Ozawa, A. Fukuoto, N. Usami, J. Yamanaka, K. Suzuki, K. Arimoto, K. Nakagawa and Y. Shiraki

Japanese Journal of Applied Physics Part 2-Letters & Express Letters   44 巻 ( 42-45 ) 頁： L1316-L1319   2005年

Growth of InGaAs and SiGe homogeneous bulk crystals which have complete miscibility in the phase diagrams

K. Nakajima, Y. Azuma, N. Usami, G. Sazaki, T. Ujihara, K. Fujiwara, T. Shishido, Y. Nishijima and T. Kusunoki

International Journal of Materials & Product Technology   22 巻   頁： 185-212   2005年

Changes in elastic deformation of strained Si by microfabrication

K. Arimoto, D. Furukawa, J. Yamanaka, K. Nakagawa, K. Sawano, S. Koh, Y. Shiraki and N. Usami

Materials Science in Semiconductor Processing   8 巻   頁： 181-185   2005年

Low-temperature growth of single-crystalline ZnO tubes on sapphire(0001) substrates

B. P. Zhang, N. T. Binh, K. Wakatsuki, N. Usami and Y. Segawa

Applied Physics a-Materials Science & Processing   79 巻 ( 7 ) 頁： 1711-1714   2004年11月

Fabrication of high-quality strain-relaxed thin SiGe layers on ion-implanted Si substrates

K. Sawano, S. Koh, Y. Shiraki, Y. Ozawa, T. Hattori, J. Yamanaka, K. Suzuki, K. Arimoto, K. Nakagawa and N. Usami

Applied Physics Letters   85 巻 ( 13 ) 頁： 2514-2516   2004年9月

On the origin of strain fluctuation in strained-Si grown on SiGe-on-insulator and SiGe virtual substrates

K. Kutsukake, N. Usami, T. Ujihara, K. Fujiwara, G. Sazaki and K. Nakajima

Applied Physics Letters   85 巻 ( 8 ) 頁： 1335-1337   2004年8月

Low-temperature growth of ZnO nanostructure networks

B. P. Zhang, K. Wakatsuki, N. T. Binh, Y. Segawa and N. Usami

Journal of Applied Physics   96 巻 ( 1 ) 頁： 340-343   2004年7月

Pressure-dependent ZnO nanocrsytal growth in a chemical vapor deposition process

B. P. Zhang, N. T. Binh, K. Wakatsuki, Y. Segawa, Y. Yamada, N. Usami, M. Kawasaki and H. Koinuma

Journal of Physical Chemistry B   108 巻   頁： 10899-10902   2004年7月

Ge composition dependence of properties of solar cells based on multicrystalline SiGe with microscopic compositional distribution

W. G. Pan, K. Fujiwara, N. Usami, T. Ujihara, K. Nakajima and R. Shimokawa

Journal of Applied Physics   96 巻 ( 2 ) 頁： 1238-1241   2004年7月

Successful growth of InxGa1-xAs (x > 0.18) single bulk crystal directly on GaAs seed crystal with preferential orientation

Y. Azuma, Y. Nishijima, K. Nakajima, N. Usami, K. Fujiwara and T. Ujihara

Japanese Journal of Applied Physics Part 2-Letters & Express Letters   43 巻 ( 7A ) 頁： L907-L909   2004年7月

Structural and optical properties of ZnO epitaxial films grown on Al2O3 (1120) substrates by metalorganic chemical vapor deposition

N. T. Binh, B. P. Zhang, C. Y. Liu, K. Wakatsuki, Y. Segawa, N. Usami, Y. Yamada, M. Kawasaki and H. Koinuma

Japanese Journal of Applied Physics Part 1-Regular Papers Short Notes & Review Papers   43 巻 ( 7A ) 頁： 4110-4113   2004年7月

Effects of growth temperature on the surface morphology of silicon thin films on (111) silicon monocrystalline substrate by liquid phase epitaxy

T. Ujihara, E. Kanda, K. Obara, K. Fujiwara, N. Usami, G. Sazaki, A. Alguno, T. Shishido and K. Nakajima

Journal of Crystal Growth   266 巻 ( 4 ) 頁： 467-474   2004年6月

Grain growth behaviors of polycrystalline silicon during melt growth processes

K. Fujiwara, Y. Obinata, T. Ujihara, N. Usami, G. Sazaki and K. Nakajima

Journal of Crystal Growth   266 巻 ( 4 ) 頁： 441-448   2004年6月

Formation of highly aligned ZnO tubes on sapphire (0001) substrates

B. P. Zhang, N. T. Binh, K. Wakatsuki, Y. Segawa, Y. Yamada, N. Usami, M. Kawasaki and H. Koinuma

Applied Physics Letters   84 巻 ( 20 ) 頁： 4098-4100   2004年3月

Effects of growth temperature on the characteristics of ZnO epitaxial films deposited by metalorganic chemical vapor deposition

B. P. Zhang, K. Wakatsuki, N. T. Binh, N. Usami and Y. Segawa

Thin Solid Films   449 巻   頁： 12-19   2004年2月

Relationship between device performance and grain boundary structural configuration in a solar cell based on multicrystalline SiGe

N. Usami, W. G. Pan, K. Fujiwara, T. Ujihara, G. Sazaki and K. Nakajima

Japanese Journal of Applied Physics Part 2-Letters   43 巻 ( 2B ) 頁： L250-L252   2004年2月

In situ observation of elementary growth steps on the surface of protein crystals by laser confocal microscopy

G. Sazaki, T. Matsui, K. Tsukamoto, N. Usami, T. Ujihara, K. Fujiwara and K. Nakajima

Journal of Crystal Growth   262 巻   頁： 536-542   2004年2月

Epitaxial relation and island growth of perylene-3.4.9.10-tetracarboxylic dianhydride (PTCDA) thin film crystals on a hydrogen-terminated Si(111) substrate

G. Sazaki, T. Fujino, J. T. Sadowski, N. Usami, T. Ujihara, K. Fujiwara, Y. Takahashi, E. Matsubara, T. Sakurai and K. Nakajima

Journal of Crystal Growth   262 巻   頁： 196-201   2004年2月

In-situ observations of melt growth behavior of polycrystalline silicon

K. Fujiwara, Y. Obinata, T. Ujhara, N. Usami, G. Sazaki and K. Nakajima

Journal of Crystal Growth   262 巻   頁： 124-129   2004年2月

Low-temperature growth of ZnO epitaxial films by metal organic chemical vapor deposition

B. P. Zhang, N. T. Binh, K. Wakatsuki, N. Usami and Y. Segawa

Applied Physics a-Materials Science & Processing   78 巻 ( 1 ) 頁： 25-28   2004年1月

Phase diagram of growth mode for the SiGe/Si heterostructure system with misfit dislocations

K. Nakajima, T. Ujihara, N. Usami, K. Fujiwara, G. Sazaki and T. Shishido

Journal of Crystal Growth   260 巻   頁： 372-383   2004年1月

Fabrication of solar cell with stacked Ge islands for enhanced absorption in the infrared regime

N. Usami, A. Alguno, K. Sawano, T. Ujihara, K. Fujiwara, G. Sazaki, Y. Shiraki and K. Nakajima

THIN SOLID FILMS   451 巻   頁： 604-607   2004年

Crystal quality evaluation of 6H-SiC layers grown by liquid phase epitaxy around micropipes using micro-Raman scattering spectroscopy

T. Ujihara, S. Munetoh, K. Kusunoki, K. Kamei, N. Usami, K. Fujiwara, G. Sazaki and K. Nakajima

MATERIALS SCIENCE FORUM   457-460 巻   頁： 633-636   2004年

Molten metal flux growth and properties of CrSi2

T. Shishido, S. Okada, Y. Ishizawa, K. Kudou, K. Iizumi, Y. Sawada, H. Horiuchi, K. Inaba, T. Sekiguchi, J. Ye, S. Miyashita, A. Nomura, T. Sugawara, K. Obara, M. Oku, K. Fujiwara, T. Ujihara, G. Sazaki, N. Usami, S. Kohiki, Y. Kawazoe and K. Nakajima

JOURNAL OF ALLOYS AND COMPOUNDS   383 巻   頁： 319-321   2004年

Fabrication of SiGe-on-insulator by rapid thermal annealing of Ge on Si-on-insulator substrate

K. Kutsukake, N. Usami, K. Fujiwara, T. Ujihara, G. Sazaki, K. Nakajima, B. P. Zhang and Y. Segawa

Appl. Surf. Sci.   224 巻 ( 1-4 ) 頁： 95-98   2004年

Effects of spacer thickness on quantum efficiency of the solar cells with embedded Ge islands in the intrinsic layer

A. Alguno, N. Usami, T. Ujihara, K. Fujiwara, G. Sazaki, K. Nakajima, K. Sawano and Y. Shiraki

Applied Physics Letters   84 巻 ( 15 ) 頁： 2802-2804   2004年

High-temperature solution growth and characterization of chromium disilicide

T. Shishido, S. Okada, Y. Ishizawa, K. Kudou, K. Iizumi, Y. Sawada, H. Horiuchi, K. Inaba, T. Sekiguchi, J. H. Ye, S. Miyashita, A. Nomura, T. Sugawara, K. Obara, Y. Murakami, K. Fujiwara, T. Ujihara, G. Sazaki, N. Usami, M. Oku, Y. Yokoyama, S. Kohiki, Y. Kawazoe and K. Nakajima

Japanese Journal of Applied Physics Part 1-Regular Papers Short Notes & Review Papers   42 巻 ( 12 ) 頁： 7292-7293   2003年12月

In-plane strain fluctuation in strained-Si/SiGe heterostructures

K. Sawano, S. Koh, Y. Shiraki, N. Usami and K. Nakagawa

Applied Physics Letters   83 巻 ( 21 ) 頁： 4339-4341   2003年11月

Optical properties of ZnO rods formed by metalorganic chemical vapor deposition

B. P. Zhang, N. T. Binh, Y. Segawa, K. Wakatsuki and N. Usami

Applied Physics Letters   83 巻 ( 8 ) 頁： 1635-1637   2003年8月

Enhanced quantum efficiency of solar cells with self-assembled Ge dots stacked in multilayer structure

A. Alguno, N. Usami, T. Ujihara, K. Fujiwara, G. Sazaki, K. Nakajima and Y. Shiraki

Applied Physics Letters   83 巻 ( 6 ) 頁： 1258-1260   2003年8月

Influence of the elastic strain on the band structure of ellipsoidal SiGe coherently embedded in the Si matrix

N. Usami, T. Ichitsubo, T. Ujihara, T. Takahashi, K. Fujiwara, G. Sazaki and K. Nakajima

Journal of Applied Physics   94 巻 ( 2 ) 頁： 916-920   2003年7月

Effects of high pressure on the growth kinetics of orthorhombic lysozyme crystals

Y. Nagatoshi, G. Sazaki, Y. Suzuki, S. Miyashita, T. Matsui, T. Ujihara, K. Fujiwara, N. Usami and K. Nakajima

Journal of Crystal Growth   254 巻   頁： 188-195   2003年6月

Growth of SiGe bulk crystals with uniform composition by utilizing feedback control system of the crystal-melt interface position for precise control of the growth temperature

Y. Azuma, N. Usami, T. Ujihara, K. Fujiwara, G. Sazaki, Y. Murakami and K. Nakajima

Journal of Crystal Growth   250 巻   頁： 298-304   2003年4月

In-plane orientation and polarity of ZnO epitaxial films on As-polished sapphire (alpha-Al2O3) (0001) substrates grown by metal organic chemical vapor deposition

B. P. Zhang, L. Manh, K. Wakatsuki, K. Tamura, T. Ohnishi, M. Lippma, N. Usami, M. Kawasaki, H. Koinuma and Y. Segawa

Japanese Journal of Applied Physics Part 2-Letters   42 巻 ( 3B ) 頁： L264-L266   2003年3月

High-quality crystalline silicon layer grown by liquid phase epitaxy method at low growth temperature

T. Ujihara, K. Obara, N. Usami, K. Fujiwara, G. Sazaki, T. Shishido and K. Nakajima

Japanese Journal of Applied Physics Part 2-Letters   42 巻 ( 3A ) 頁： L217-L219   2003年3月

Fabrication of SiGe-on-insulator through thermal diffusion of Ge on Si-on-insulator substrate

K. Kutsukake, N. Usami, K. Fujiwara, T. Ujihara, G. Sazaki, B. P. Zhang, Y. Segawa and K. Nakajima

Japanese Journal of Applied Physics Part 2-Letters   42 巻 ( 3A ) 頁： L232-L234   2003年3月

Epitaxial growth and polarity of ZnO films on sapphire (0001) substrates by low-pressure metal organic chemical vapor deposition

B. P. Zhang, L. H. Manh, K. Wakatsuki, T. Ohnishi, M. Lippmaa, N. Usami, M. Kawasaki and Y. Segawa

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS   42 巻   頁： 2291-2295   2003年

Planarization of SiGe virtual substrates by CMP and its application to strained Si modulation-doped structures

K. Sawano, K. Arimoto, Y. Hirose, S. Koh, N. Usami, K. Nakagawa, T. Hattori and Y. Shiraki

JOURNAL OF CRYSTAL GROWTH   251 巻 ( 1-4 ) 頁： 693-696   2003年

3D atomic imaging of SiGe system by X-ray fluorescence holography

K. Hayashi, Y. Takahashi, E. Matsubara, K. Nakajima and N. Usami

J. Materials Science: Materials in Electronics   14 巻   頁： 459-462   2003年

Strain distribution of Si thin film grown on multicrystalline-SiGe with microscopic compositional distribution

N. Usami, T. Takahashi, K. Fujiwara, T. Ujihara, G. Sazaki, Y. Murakami and K. Nakajima

Journal of Applied Physics   92 巻 ( 12 ) 頁： 7098-7101   2002年12月

In situ observations of crystal growth behavior of silicon melt

K. Fujiwara, K. Nakajima, T. Ujihara, N. Usami, G. Sazaki, H. Hasegawa and S. Mizoguchi

Journal of Crystal Growth   243 巻 ( 2 ) 頁： 275-282   2002年8月

Evidence of the presence of built-in strain in multicrystalline SiGe with large compositional distribution

N. Usami, T. Takahashi, K. Fujiwara, T. Ujihara, G. Sazaki, Y. Murakami and K. Nakajima

Japanese Journal of Applied Physics Part 1-Regular Papers Short Notes & Review Papers   41 巻 ( 7A ) 頁： 4462-4465   2002年7月

Simultaneous in situ measurement of solute and temperature distributions in the alloy solutions

T. Ujihara, K. Fujiwara, G. Sazaki, N. Usami and K. Nakajima

Journal of Crystal Growth   242 巻   頁： 313-320   2002年7月

Preparation of a TiO2 film coated Si device for photo-decomposition of water by CVD method using Ti(OPri)(4)

N. Sato, K. Nakajima, N. Usami, H. Takahashi, A. Muramatsu and E. Matsubara

Materials Transactions   43 巻 ( 7 ) 頁： 1533-1536   2002年7月

Growth and properties of SiGe multicrystals with microscopic compositional distribution for high-efficiency solar cells

K. Nakajima, N. Usami, K. Fujiwara, Y. Murakami, T. Ujihara, G. Sazaki and T. Shishido

Solar Energy Materials and Solar Cells   73 巻 ( 3 ) 頁： 305-320   2002年7月

New method for measurement of interdiffusion coefficient in high temperature solutions based on Fick's first law

T. Ujihara, K. Fujiwara, G. Sazaki, N. Usami and K. Nakajima

Journal of Crystal Growth   241 巻 ( 3 ) 頁： 387-394   2002年6月

Compositional variation in Si-rich SiGe single crystals grown by multi-component zone melting method using Si seed and source crystals

K. Nakajima, T. Kusunoki, Y. Azuma, N. Usami, K. Fujiwara, T. Ujihara, G. Sazaki and T. Shishido

Journal of Crystal Growth   240 巻   頁： 373-381   2002年5月

Melt growth of multicrystalline SiGe with large compositional distribution for new solar cell applications

K. Nakajima, N. Usami, K. Fujiwara, Y. Murakami, T. Ujihara, G. Sazaki and T. Shishido

Solar Energy Materials and Solar Cells   72 巻   頁： 93-100   2002年4月

In-situ monitoring system of the position and temperature at the crystal-solution interface

G. Sazaki, Y. Azuma, S. Miyashita, N. Usami, T. Ujihara, K. Fujiwara, Y. Murakami and K. Nakajima

Journal of Crystal Growth   236 巻   頁： 125-131   2002年3月

Control of macroscopic absorption coefficient of multicrystalline SiGe by microscopic compositional distribution

N. Usami, K. Fujiwara, T. Ujihara, G. Sazaki, H. Yaguchi, Y. Murakami and K. Nakajima

Japanese Journal of Applied Physics Part 2-Letters   41 巻 ( 1AB ) 頁： L37-L39   2002年1月

In situ observation of the Marangoni convection in a NaCl aqueous solutions under microgravity

G. Sazaki, S. Miyashita, M. Nokura, T. Ujihara, K. Fujiwara, N. Usami and K. Nakajima

Journal of Crystal Growth   234 巻   頁： 516-522   2002年1月

Raman scattering and x-ray absorption studies of Ge-Si nanocrystallization

A. Kolobov, H. Oyanagi, N. Usami, S. Tokumitsu, T. Hattori, S. Yamasaki, K. Tanaka, S. Ohtake and Y. Shiraki

Applied Physics Letters   80 巻 ( 3 ) 頁： 488-490   2002年1月

Effect of Si diffusion on growth, parameters and photoluminescence of GeSi/Si(001) self-assembled islands

M. Y. Valakh, N. V. Vostokov, S. A. Gusev, Y. N. Drozdov, Z. F. Krasil'nik, D. N. Lobanov, L. D. Moldavskaya, A. V. Novikov, V. V. Postnikov, M. V. Stepikhova, N. Usami, Y. Shiraki and V. A. Yukhymchuk

IZVESTIYA AKADEMII NAUK SERIYA FIZICHESKAYA   66 巻   頁： 161-164   2002年

Fabrication of SiGe bulk crystals with uniform composition as substrates for Si-based heterostructures

N. Usami, Y. Azuma, T. Ujihara, G. Sazaki, K. Fujiwara, Y. Murakami and K. Nakajima

MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY   89 巻   頁： 364-367   2002年

Evaluation of the diffusion coefficients in liquid GaGe binary alloys using a novel method based on Fick's first law

T. Ujihara, K. Fujiwara, G. Sazaki, N. Usami and K. Nakajima

JOURNAL OF NON-CRYSTALLINE SOLIDS   312 巻   頁： 196-202   2002年

Strain-driven alloying: effect on sizes, shape and photoluminescence of GeSi/Si(001) self-assembled islands

A. V. Novikov, B. A. Andreev, N. V. Vostokov, Y. N. Drozdov, Z. F. Krasilnik, D. N. Lobanov, L. D. Moldavskaya, A. N. Yablonskiy, M. Miura, N. Usami, Y. Shiraki, M. Y. Valakh, N. Mestres and J. Pascual

MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY   89 巻   頁： 62-65   2002年

Molecular beam epitaxy of GaAs on nearly lattice-matched SiGe substrates grown by the multicomponent zone-melting method

N. Usami, Y. Azuma, T. Ujihara, G. Sazaki, K. Nakajima, Y. Yakabe, T. Kondo, K. Kawaguchi, S. Koh, Y. Shiraki, B. P. Zhang, Y. Segawa and S. Kodama

Semiconductor Science and Technology   16 巻 ( 8 ) 頁： 699-703   2001年8月

Physical model for the evaluation of solid-liquid interfacial tension in silicon

T. Ujihara, G. Sazaki, K. Fujiwara, N. Usami and K. Nakajima

Journal of Applied Physics   90 巻 ( 2 ) 頁： 750-755   2001年7月

Fabrication of strain-balanced Si/Si1-xGex multiple quantum wells on Si1-yGey virtual substrates and their optical properties

K. Kawaguchi, Y. Shiraki, N. Usami, J. Zhang, N. J. Woods, G. Breton and G. Parry

Applied Physics Letters   79 巻 ( 3 ) 頁： 344-346   2001年7月

Growth of SixGe1-x (x=0.15) bulk crystal with uniform composition utilizing in situ monitoring of the crystal-solution interface

N. Usami, Y. Azuma, T. Ujihara, G. Sazaki, S. Miyashita, Y. Murakami and K. Nakajima

Japanese Journal of Applied Physics Part 1-Regular Papers Short Notes & Review Papers   40 巻 ( 6A ) 頁： 4141-4144   2001年6月

Growth of SiGe bulk crystal with uniform composition by directly controlling the growth temperature at the crystal-melt inter-face using in situ monitoring system

Y. Azuma, N. Usami, T. Ujihara, G. Sazaki, Y. Murakami, S. Miyashita, K. Fujiwara and K. Nakajima

Journal of Crystal Growth   224 巻   頁： 204-211   2001年4月

The relation between composition and sizes of GeSi/Si(001) islands grown at different temperatures

N. V. Vostokov, S. A. Gusev, Y. N. Drozdov, Z. F. Krasilnik, D. N. Lobanov, N. Mesters, M. Miura, L. D. Moldavskaya, A. V. Novikov, J. Pascual, V. V. Postnikov, Y. Shiraki, V. A. Uakhimchuk, N. Usami and M. Y. Valakh

PHYSICS OF LOW-DIMENSIONAL STRUCTURES   41337 巻   頁： 295-301   2001年

Modification of the growth mode of Ge on Si(100) in the presence of buried Ge islands

N. Usami, M. Miura, Y. Ito, Y. Araki, K. Nakajima and Y. Shiraki

JOURNAL OF CRYSTAL GROWTH   227 巻   頁： 782-785   2001年

Observation of negatively charged excitons and excited states of multi-excitons in quantum dots embedded in modulation doping structures

K. Ohdaira, N. Usami, K. Ota and Y. Shiraki

PHYSICA E   11 巻 ( 2-3 ) 頁： 68-71   2001年

Phase diagram calculation for epitaxial growth of GaInAs on InP considering the surface, interfacial and strain energies

K. Nakajima, T. Ujihara, G. Sazaki and N. Usami

Journal of Crystal Growth   220 巻 ( 4 ) 頁： 413-424   2000年12月

SiGe bulk crystal as a lattice-matched substrate to GaAs for solar cell applications

N. Usami, Y. Azuma, T. Ujihara, G. Sazaki, K. Nakajima, Y. Yakabe, T. Kondo, S. Koh, Y. Shiraki, B. Zhang, Y. Segawa and S. Kodama

Applied Physics Letters   77 巻 ( 22 ) 頁： 3565-3567   2000年11月

In situ measurement of composition in high-temperature solutions by X-ray fluorescence spectrometry

T. Ujihara, G. Sazaki, S. Miyashita, N. Usami and K. Nakajima

Japanese Journal of Applied Physics Part 1-Regular Papers Short Notes & Review Papers   39 巻 ( 10 ) 頁： 5981-5982   2000年10月

Drastic increase of the density of Ge islands by capping with a thin Si layer

N. Usami, M. Miura, Y. Ito, Y. Araki and Y. Shiraki

Applied Physics Letters   77 巻 ( 2 ) 頁： 217-219   2000年7月

Modification of the growth mode of Ge on Si by buried Ge islands

N. Usami, Y. Araki, Y. Ito, M. Miura and Y. Shiraki

Applied Physics Letters   76 巻 ( 25 ) 頁： 3723-3725   2000年6月

Optical investigation of modified Stranski-Krastanov growth mode in the stacking of self-assembled Ge islands

N. Usami and Y. Shiraki

THIN SOLID FILMS   369 巻   頁： 108-111   2000年

Microscopic probing of localized excitons in quantum wells

N. Usami, K. Ota, K. Ohdaira, Y. Shiraki, T. Hasche, V. Lyssenko and K. Leo

INSTITUTE OF PHYSICS CONFERENCE SERIES   ( 166 ) 頁： 99-102   2000年

Drastic modification of the growth mode of Ge quantum dots on Si by using boron adlayer

H. Takamiya, M. Miura, N. Usami, T. Hattori and Y. Shiraki

THIN SOLID FILMS   369 巻 ( 1-2 ) 頁： 84-87   2000年

Growth and characterization of Ge-70(n)/Ge-74(n) isotope superlattices

K. Morita, K. M. Itoh, J. Muto, K. Mizoguchi, N. Usami, Y. Shiraki and E. E. Haller

THIN SOLID FILMS   369 巻 ( 1-2 ) 頁： 405-408   2000年

Formation of relaxed SiGe films on Si by selective epitaxial growth

K. Kawaguchi, N. Usami and Y. Shiraki

Thin Solid Films   369 巻   頁： 126-129   2000年

Correlation between electronic states and optical properties in indirect GaAsP/GaP quantum wells with insertion of an ultrathin AlP layer

K. Arimoto, N. Usami and Y. Shiraki

Physica E   8 巻   頁： 323-327   2000年

Effect of the insertion of an ultrathin AlP layer on the optical properties of GaAsP/GaP quantum wells

K. Arimoto, T. Sugita, N. Usami and Y. Shiraki

Physical Review B   60 巻 ( 19 ) 頁： 13735-13739   1999年11月

Magnetophotoluminescence spectroscopy of AlGaP-based neighboring confinement structures

N. Usami, T. Sugita, T. Ohta, F. Issiki, Y. Shiraki, K. Uchida and N. Miura

Physical Review B   60 巻 ( 3 ) 頁： 1879-1883   1999年7月

Study of a pure-Ge/Si short-period superlattice by x-ray double crystal diffraction

Z. G. Ji, H. M. Lu, S. G. Zhang, D. L. Que, N. Usami, H. Sunamura and Y. Shiraki

Journal of Materials Synthesis and Processing   7 巻 ( 3 ) 頁： 205-207   1999年5月

Selective epitaxial growth of dot structures on patterned Si substrates by gas source molecular beam epitaxy

E. S. Kim, N. Usami and Y. Shiraki

Semiconductor Science and Technology   14 巻 ( 3 ) 頁： 257-265   1999年3月