Visiting Professor, Institute of Fluid Science, Tohoku University

2013.5 - 2017.3

Tohoku University   Institute for Materials Research   Associate professor

2007.4 - 2013.3

Tohoku University   Institute for Materials Research   Associate Professor

2000.2 - 2007.3

Technical University of Dresden   Institute for Applied Photophysics   Visiting Researcher

1998.3 - 1999.1

The University of Tokyo   Research Center for Advanced Science and Technology   Assistant

1994.7 - 2000.1

Material Research Society

3rd International Symposium on Crytal Growth Processes and Devices   Member of Scientific Advisory Committee  

2022.4 - 2023.3   

Indo-Japan Joint Workshop on Photovoltaics   Convenor  

2022.4 - 2023.3   

NIMS次期拠点プロジェクト   外部評価委員  

2021.10   

APAC Silicide 2022   Program committee member  

2021.9 - 2023.3   

宮﨑大学テニュアトラック教員選考評価委員会   委員  

2021.9   

日本学術振興会産学協力委員会R032産業イノベーションのための結晶成長委員会   運営委員  

2021.7   

9th International Symposium on Control of Semiconductor Interfaces   International Program Committee  

2021.4 - 2023.3   

多結晶材料情報学応用技術研究会   座長  

2021.4 - 2023.3   

新エネルギー・産業技術総合開発機構   技術委員  

2021.1 - 2026.3   

次世代の太陽光発電シンポジウム   プログラム委員  

2020.10   

日本太陽光発電学会次世代セル・モジュール分科会   幹事  

2020.10   

International Advisory Committee of the International Photovoltaic Science and Engineering Conference   member  

2020.8   

International Advisory Committee of World Conference on Photovoltaic Energy Conversion   member  

2020.8   

The 22nd International Vacuum Congress   Chair of sub-program committee, Electronic Materials and Processing  

2020.4 - 2023.3   

第8回シリコン材料の先端科学と技術国際シンポジウム   実行委員  

2020.4 - 2023.3   

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

2019 - 2021.3   

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

2018.12 - 2023.3   

  Member of the international advisory committee  

2018.4 - 2022.4   

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

2016.4 - 2018.4   

東北大学金属材料研究所研究部共同利用委員会   委員  

2016.4 - 2018.3   

東北大学産学連携先端材料研究開発センター運営評議委員会   委員  

2015.4 - 2019.3   

日本学術振興会結晶加工と評価技術第145委員会   幹事  

2013 - 2023.3   

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 - 2020.3   

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

2006.10   

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 - 2021.3   

イノベイティブPV論文賞

2017.7   独立行政法人日本学術振興会   多結晶材料情報学によるスマートシリコンインゴットの創製に向けて

"宇佐美徳隆、羽山優介、髙橋勲、松本哲也、工藤博章、横井達矢、松永克志、沓掛健太朗、大野裕 "

The best poster award

2012.6  

The best paper award

2009.11  

インテリジェント・コスモス奨励賞

2008.8   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

2000.7   一般財団法人安藤研究所  

Engineering Conference Foundation Fellowship on Silicon Heterostructrues

1997.9  

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

1993.8  

Microstructural, electrical, and optoelectronic properties of BaSi2 epitaxial films grown on Si substrates by close-spaced evaporation Reviewed International journal

Hara Kosuke O., Takagaki Ryota, Arimoto Keisuke, Usami Noritaka

JOURNAL OF ALLOYS AND COMPOUNDS   Vol. 966   2023.12

Free-Standing Electrode and Fixed Surface Tiny Electrode Implemented Triboelectric Nanogenerator with High Instantaneous Current Reviewed International coauthorship

Haitao Wang, Yasuyoshi Kurokawa, Jia Wang, Wentao Cai, Jia-Han Zhang, Shinya Kato, Noritaka Usami

Small     page： 2308531-1 - 2308531-9   2023.12

Multicrystalline Informatics Applied to Multicrystalline Silicon for Unraveling The Microscopic Root Cause of Dislocation Generation Reviewed

Kenta Yamakoshi, Yutaka Ohno, Kentaro Kutsukake, Takuto Kojima, Tatsuya Yokoi, Hideto Yoshida, Hiroyuki Tanaka, Xin Liu, Hiroaki Kudo, Noritaka Usami

Advanced Materials     page： 2308599-1 - 2308599-13   2023.12

Hydrogenation of silicon-nanocrystals-embedded silicon oxide passivating contacts Invited Reviewed International journal

Masashi Matsumi, Kazuhiro Gotoh, Markus Wilde, Yasuyoshi Kurokawa, Katsuyuki Fukutani and Noritaka Usami

Nanotechnology     2023.11

Nanoscale Size Control of Si Pyramid Texture for Perovskite/Si Tandem Solar Cells Enabling Solution‐Based Perovskite Top‐Cell Fabrication and Improved Si Bottom‐Cell Response Reviewed International journal

Yuqing Li, Hitoshi Sai, Calum McDonald, Zhihao Xu, Yasuyoshi Kurokawa, Noritaka Usami, Takuya Matsui

Advanced Materials Interfaces     page： 2300504-1 - 2300504-9   2023.9

Improvement of passivation performance of silicon nanocrystal/silicon oxide compound layer by two-step hydrogen plasma treatment Reviewed International journal

Masashi Matsumi, Kazuhiro Gotoh, Markus Wilde, Yasuyoshi Kurokawa, Katsuyuki Fukutani, Noritaka Usami

Solar Energy Materials and Solar Cells   Vol. 262   page： 112358-1 - 112358-6   2023.9

Thermoelectric properties of Mg2Si thin films prepared by thermal evaporation of Mg and face-to-face annealing Reviewed International journal

Kurokawa Yasuyoshi, Sato Kaisei, Shibata Keisuke, Kato Shinya, Miyamoto Satoru, Gotoh Kazuhiro, Itoh Takashi, Usami Noritaka

MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING   Vol. 163   2023.8

Quantitative evaluation of implied open-circuit voltage after metal electrode deposition on TiO (x) /Si heterostructures by photoluminescence imaging: impact of metallization on passivation performance Reviewed International journal

Fukaya Shohei, Gotoh Kazuhiro, Matsui Takuya, Sai Hitoshi, Kurokawa Yasuyoshi, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 62 ( SK )   2023.8

Impact of B2H6 plasma treatment on contact resistivity in silicon heterojunction solar cells Reviewed International journal

Gotoh Kazuhiro, Ozaki Ryo, Morimura Motoo, Tanaka Aki, Iseki Yoshiko, Nakamura Kyotaro, Muramatsu Kazuo, Kurokawa Yasuyoshi, Ohshita Yoshio, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 62 ( SK )   2023.8

3D CNN and grad-CAM based visualization for predicting generation of dislocation clusters in multicrystalline silicon Reviewed International journal

Kyoka Hara, Takuto Kojima, Kentaro Kutsukake, Hiroaki Kudo, and Noritaka Usami

APL Machine Learning   Vol. 1   page： 036106-1 - 036106-9   2023.7

A machine learning-based prediction of crystal orientations for multicrystalline materials Reviewed International journal

Kyoka Hara, Takuto Kojima, Kentaro Kutsukake, Hiroaki Kudo, and Noritaka Usami

APL Machine Learning   Vol. 1   page： 026113-1 - 026113-9   2023.5

Fabrication of light trapping structures specialized for near-infrared light by nanoimprinting for the application to thin crystalline silicon solar cells Reviewed International journal

Kimata Yuto, Gotoh Kazuhiro, Miyamoto Satoru, Kato Shinya, Kurokawa Yasuyoshi, Usami Noritaka

DISCOVER NANO   Vol. 18 ( 1 )   2023.5

Preparation and thermoelectric characterization of boron-doped Si nanocrystals/silicon oxide multilayers Reviewed International journal

Keisuke Shibata, Shinya Kato, Masashi Kurosawa, Kazuhiro Gotoh, Satoru Miyamoto, Noritaka Usami and Yasuyoshi Kurokawa

Japanese Journal of Applied Physics   Vol. 62 ( SC ) page： SC1074   2023.4

Performance enhancement of droplet-based electricity generator using a CYTOP intermediate layer Reviewed International journal

Haitao Wang, Yasuyoshi Kurokawa, Kazuhiro Gotoh, Shinya Kato, Shigeru Yamada, Takashi Itoh and Noritaka Usami

Japanese Journal of Applied Physics   Vol. 62 ( SC ) page： SC1032   2023.4

The impact on mc-Si ingot grown in a directional solidification furnace by partially replacing the susceptor bottom with an insulation material: A numerical investigation Reviewed International coauthorship International journal

T. Keerthivasan, Xin Liu, M. Srinivasan, Noritaka Usami, G. Anbu, G. Aravindan, P. Ramasamy

Journal of Crystal Growth   Vol. 607   page： 127130-1 - 127130-7   2023.4

Bayesian optimization of hydrogen plasma treatment in silicon quantum dot multilayer and application to solar cells Reviewed International journal

Fuga Kumagai, Kazuhiro Gotoh, Satoru Miyamoto, Shinya Kato, Kentaro Kutsukake, Noritaka Usami and Yasuyoshi Kurokawa

Discover Nano   Vol. 43   2023.3

Evaluation of Damage in Crystalline Silicon Substrate Induced by Plasma Enhanced Chemical Vapor Deposition of Amorphous Silicon Films Reviewed International journal

H. Kojima, T. Nishihara, K. Gotoh, N. Usami, T. Hara, K. Nakamura, Y. Ohshita, and A. Ogura

ECS Journal of Solid State Science and Technology   Vol. 12 ( 1 ) page： 015003   2023.1

Influence of post-oxidizing treatment on passivation performance on the spin-coated titanium oxide films on crystalline silicon Reviewed International journal

Thin Solid Films   Vol. 764   page： 139597   2023.1

Quantitative evaluation of implied open-circuit voltage after metal electrode deposition on TiOx/Si heterostructures by photoluminescence imaging: Impact of metallization on passivation performance Invited Reviewed International journal

Shohei Fukaya, Kazuhiro Gotoh, Takuya Matsui, Hitoshi Sai, Yasuyoshi Kurokawa, Noritaka Usami

Japanese Journal of Applied Physics     2023

Influence of insertion position of a LiF buffer layer on passivation performance of crystalline Si/SiO<i>_y</i> /TiO<i>_x</i>/Al heterostructures

Fukaya, S; Gotoh, K; Matsui, T; Sai, H; Kurokawa, Y; Usami, N

2023 IEEE 50TH PHOTOVOLTAIC SPECIALISTS CONFERENCE, PVSC     2023

Evaluation of process damage to crystalline silicon by transparent conductive oxide film deposition

Kojima, H; Nishihara, T; Ito, Y; Lee, H; Gotoh, K; Usami, N; Hara, T; Nakamura, K; Ohsita, Y; Ogura, A

2023 IEEE 50TH PHOTOVOLTAIC SPECIALISTS CONFERENCE, PVSC     2023

Impurity analysis of the effect of partial replacement of retort with an insulation material on mc-silicon grown in directional solidification furnace: Computational Modeling Reviewed International coauthorship International journal

T. Keerthivasan, X. Liu, M. Srinivasan, N. Usami, G. Aravindan, P. Ramasamy

Journal of Crystal Growth   Vol. 599   page： 126892   2022.12

Analysis of grain growth behavior of multicrystalline Mg2Si Reviewed International journal

Deshimaru Takumi, Yamakoshi Kenta, Kutsukake Kentaro, Kojima Takuto, Umehara Tsubasa, Udono Haruhiko, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 62 ( SD )   2022.11

Nanopyramid Texture Formation by One-Step Ag-Assisted Solution Process for High-Efficiency Monocrystalline Si Solar Cells Reviewed International journal

Li Yuqing, Sai Hitoshi, Matsui Takuya, Xu Zhihao, Nguyen Van Hoang, Kurokawa Yasuyoshi, Usami Noritaka

SOLAR RRL   Vol. 6 ( 11 )   2022.9

Epitaxial growth of SiGe films by annealing Al–Ge alloyed pastes on Si substrate Reviewed International journal

Keisuke Fukuda, Satoru Miyamoto, Masahiro Nakahara, Shota Suzuki, Marwan Dhamrin, Kensaku Maeda, Kozo Fujiwara, Yukiharu Uraoka and Noritaka Usami

Scientific Reports   Vol. 12 ( 1 )   2022.9

Study on electrical activity of grain boundaries in silicon through systematic control of structural parameters and characterization using a pretrained machine learning model Reviewed International journal

Fukuda Yusuke, Kutsukake Kentaro, Kojima Takuto, Ohno Yutaka, Usami Noritaka

JOURNAL OF APPLIED PHYSICS   Vol. 132 ( 2 )   2022.7

Estimation of Crystal Orientation of Grains on Polycrystalline Silicon Substrate by Recurrent Neural Network Reviewed International journal

Kato Hikaru, Kamibeppu Soichiro, Kojima Takuto, Matsumoto Tetsuya, Kudo Hiroaki, Takeuchi Yoshinori, Kutsukake Kentaro, Usami Noritaka

IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING   Vol. 17 ( 11 ) page： 1685 - 1687   2022.7

Fabrication of BaSi2 homojunction diodes on Nb-doped TiO2 coated glass substrates by aluminum-induced crystallization and two-step evaporation method Reviewed International journal

Kurokawa Yasuyoshi, Yoshino Takamasa, Gotoh Kazuhiro, Miyamoto Satoru, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 61 ( SC )   2022.5

Improved conversion efficiency of p-type BaSi2/n-type crystalline Si heterojunction solar cells by a low growth rate deposition of BaSi2 Invited Reviewed International journal

Fujiwara Michinobu, Takahashi Kazuma, Nakagawa Yoshihiko, Gotoh Kazuhiro, Itoh Takashi, Kurokawa Yasuyoshi, Usami Noritaka

AIP ADVANCES   Vol. 12 ( 4 )   2022.4

Zn1-xGexOy Passivating Interlayers for BaSi2 Thin-Film Solar Cells Reviewed

Yamashita Yudai, Takayanagi Kaori, Gotoh Kazuhiro, Toko Kaoru, Usami Noritaka, Suemasu Takashi

ACS APPLIED MATERIALS & INTERFACES   Vol. 14 ( 11 ) page： 13828 - 13835   2022.3

Effects of grain boundary structure and shape of the solid-liquid interface on the growth direction of the grain boundaries in multicrystalline silicon Reviewed International journal

Fukuda Yusuke, Kutsukake Kentaro, Kojima Takuto, Usami Noritaka

CRYSTENGCOMM   Vol. 24 ( 10 ) page： 1948 - 1954   2022.3

Data-Driven Optimization and Experimental Validation for the Lab-Scale Mono-Like Silicon Ingot Growth by Directional Solidification Reviewed International journal

Xin Liu, Yifan Dang, Hiroyuki Tanaka, Yusuke Fukuda, Kentaro Kutsukake, Takuto Kojima, Toru Ujihara, and Noritaka Usami

ACS Omega   Vol. 7 ( 8 ) page： 6665 - 6673   2022.3

Silicon Nanocrystals Embedded in Nanolayered Silicon Oxide for Crystalline Silicon Solar Cells Reviewed International journal

Tsubata Ryohei, Gotoh Kazuhiro, Matsumi Masashi, Wilde Markus, Inoue Tetsuya, Kurokawa Yasuyoshi, Fukutani Katsuyuki, Usami Noritaka

ACS APPLIED NANO MATERIALS   Vol. 5 ( 2 )   2022.2

Zn_1-x Ge_x O_y Passivating Interlayers for BaSi2 Thin-Film Solar Cells Reviewed International journal

Yudai Yamashita, Kaori Takayanagi, Kazuhiro Gotoh, Kaoru Toko, Noritaka Usami, and Takashi Suemasu

ACS Appl. Mater. Interfaces     2022.2

Fabrication of BaSi₂ homojunction diodes on Nb-doped TiO2 coated glass substrates by aluminum-induced crystallization and two-step evaporation method Reviewed International journal

Japanese Journal of Applied Physics     2022.2

Effects of grain boundary structure and shape of the solid–liquid interface on the growth direction of the grain boundaries in multicrystalline silicon Reviewed International journal

Yusuke Fukuda, Kentaro Kutsukake, Takuto Kojima, Noritaka Usami

CrystEngComm     2022.2

Silicon Nanocrystals Embedded in Nanolayered Silicon Oxide for Crystalline Silicon Solar Cells Reviewed International journal

ACS Appl. Nano Mater.   Vol. 5 ( 2 ) page： 1820 - 187   2022.1

Fractal dimension analogous scale-invariant derivative of Hirsch's index Reviewed International journal

Fujita Yuji, Usami Noritaka

APPLIED NETWORK SCIENCE   Vol. 7 ( 1 )   2022.1

Fine Line Screen-Printing Aluminum for Front side p(+) Metallization of High Efficiency Solar Cells Reviewed International coauthorship International journal

Tsuji Kosuke, Suzuki Shota, Dhamrin Marwan, Adrian Adrian, Buck Thomas, Usami Noritaka

11TH INTERNATIONAL CONFERENCE ON CRYSTALLINE SILICON PHOTOVOLTAICS (SILICONPV 2021)   Vol. 2487   2022

Impact of chemically grown silicon oxide interlayers on the hydrogen distribution at hydrogenated amorphous silicon/crystalline silicon heterointerfaces Reviewed International journal

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

APPLIED SURFACE SCIENCE   Vol. 567   2021.11

Fabrication of heterojunction crystalline Si solar cells with BaSi2 thin films prepared by a two-step evaporation method Reviewed International journal

Nakagawa Yoshihiko, Takahashi Kazuma, Fujiwara Michinobu, Hara Kosuke O., Gotoh Kazuhiro, Kurokawa Yasuyoshi, Itoh Takashi, Suemasu Takashi, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 60 ( 10 )   2021.10

Improved Performance of Titanium Oxide/Silicon Oxide Electron-Selective Contacts by Implementation of Magnesium Interlayers International journal

Nakagawa Yuta, Gotoh Kazuhiro, Inoue Tetsuya, Kurokawa Yasuyoshi, Usami Noritaka

PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE   Vol. 218 ( 19 )   2021.10

Bayesian Optimization of Passivating Contacts for Crystalline Silicon Solar Cells Invited Reviewed International journal

ECS Meeting Abstracts     2021.10

Contact control of Al/Si interface of Si solar cells by local contact opening method Reviewed International coauthorship International journal

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

MATERIALS CHEMISTRY AND PHYSICS   Vol. 270   2021.9

Application of Bayesian optimization for high-performance TiOx/SiOy/c-Si passivating contact Reviewed International journal

Miyagawa Shinsuke, Gotoh Kazuhiro, Kutsukake Kentaro, Kurokawa Yasuyoshi, Usami Noritaka

SOLAR ENERGY MATERIALS AND SOLAR CELLS   Vol. 230   2021.9

Fabrication of Silicon Nanowire Metal-Oxide-Semiconductor Capacitors with Al2O3/TiO2/Al2O3 Stacked Dielectric Films for the Application to Energy Storage Devices Reviewed International journal

Nezasa Ryota, Gotoh Kazuhiro, Kato Shinya, Miyamoto Satoru, Usami Noritaka, Kurokawa Yasuyoshi

ENERGIES   Vol. 14 ( 15 )   2021.8

Direct prediction of electrical properties of grain boundaries from photoluminescence profiles using machine learning Reviewed International journal

Kutsukake Kentaro, Mitamura Kazuki, Usami Noritaka, Kojima Takuto

APPLIED PHYSICS LETTERS   Vol. 119 ( 3 )   2021.7

Occurrence Prediction of Dislocation Regions in Photoluminescence Image of Multicrystalline Silicon Wafers Using Transfer Learning of Convolutional Neural Network Reviewed International journal

Kudo Hiroaki, Matsumoto Tetsuya, Kutsukake Kentaro, Usami Noritaka

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   Vol. E104A ( 6 ) page： 857 - 865   2021.6

Passivation mechanism of the high-performance titanium oxide carrier-selective contacts on crystalline silicon studied by spectroscopic ellipsometry Reviewed International journal

Gotoh Kazuhiro, Miura Hiroyuki, Shimizu Ayako, Kurokawa Yasuyoshi, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 60 ( SB )   2021.5

Mechanisms of carrier lifetime enhancement and conductivity-type switching on hydrogen-incorporated arsenic-doped BaSi2 Reviewed International journal

Aonuki Sho, Xu Zhihao, Yamashita Yudai, Gotoh Kazuhiro, Toko Kaoru, Usami Noritaka, Filonov Andrew B., Nikitsiuk Siarhei A., Migas Dmitri B., Shohonov Denis A., Suemasu Takashi

THIN SOLID FILMS   Vol. 724   2021.4

Versatile fabrication of a passivation material, solute PEDOT:PSS, for a c-Si substrate using alcoholic solvents Reviewed International coauthorship International journal

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

SUSTAINABLE ENERGY & FUELS   Vol. 5 ( 3 ) page： 666 - 670   2021.2

Application of Bayesian optimization for improved passivation performance in TiOx/SiOy/c-Si heterostructure by hydrogen plasma treatment Reviewed International journal

Miyagawa Shinsuke, Gotoh Kazuhiro, Kutsukake Kentaro, Kurokawa Yasuyoshi, Usami Noritaka

APPLIED PHYSICS EXPRESS   Vol. 14 ( 2 )   2021.2

Simulation study on lateral minority carrier transport in the surface inversion layer of the p-aSi:H/i-aSi:H/cSi heterojunction solar cell Reviewed International journal

Kamioka Takefumi, Hayashi Yutaka, Gotoh Kazuhiro, Hara Tomohiko, Ozaki Ryo, Morimura Motoo, Shimizu Ayako, Nakamura Kyotaro, Usami Noritaka, Ogura Atsushi, Ohshita Yoshio

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 60 ( 2 )   2021.2

Propagation of Crystal Defects during Directional Solidification of Silicon via Induction of Functional Defects International coauthorship International journal

Patricia Krenckel , Yusuke Hayama, Florian Schindler, Theresa Trötschler, Stephan Riepe and Noritaka Usami

Crystals   Vol. 11 ( 2 ) page： 1 - 10   2021.2

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 Reviewed International journal

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

APPLIED PHYSICS EXPRESS   Vol. 14 ( 1 ) page： .   2021.1

Activation energy of hydrogen desorption from high-performance titanium oxide carrier-selective contacts with silicon oxide interlayers Reviewed International journal

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

CURRENT APPLIED PHYSICS   Vol. 21   page： 36 - 42   2021.1

Realization of the Crystalline Silicon Solar Cell Using Nanocrystalline Transport Path in Ultra-thin Dielectrics for Reinforced Passivating Contact

Tsubata Ryohei, Gotoh Kazuhiro, Inoue Tetsuya, Kurokawa Yasuyoshi, Usami Noritaka

2021 IEEE 48TH PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC)     page： 908 - 911   2021

The impact of highly excessive PbI2 on the correlation of MAPbI(3) perovskite morphology and carrier lifetimes Reviewed International coauthorship International journal

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

JOURNAL OF MATERIALS CHEMISTRY C   Vol. 8 ( 41 ) page： 14481 - 14489   2020.11

Generation of dislocation clusters at triple junctions of random angle grain boundaries during cast growth of silicon ingots Reviewed International journal

Ohno Yutaka, Tajima Kazuya, Kutsukake Kentaro, Usami Noritaka

APPLIED PHYSICS EXPRESS   Vol. 13 ( 10 )   2020.10

Determination of carrier recombination velocity at inclined grain boundaries in multicrystalline silicon through photoluminescence imaging and carrier simulation Reviewed International journal

Mitamura Kazuki, Kutsukake Kentaro, Kojima Takuto, Usami Noritaka

JOURNAL OF APPLIED PHYSICS   Vol. 128 ( 12 )   2020.9

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 Reviewed International coauthorship International journal

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

MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING   Vol. 114   2020.8

Reactive deposition growth of highly (001)-oriented BaSi2 films by close-spaced evaporation Reviewed International journal

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

MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING   Vol. 113   2020.7

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 Reviewed International coauthorship International journal

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   Vol. 127 ( 23 )   2020.6

Impact of deposition of indium tin oxide double layers on hydrogenated amorphous silicon/crystalline silicon heterojunction Reviewed International journal

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

AIP ADVANCES   Vol. 10 ( 6 )   2020.6

Significant enhancement of photoresponsivity in As-doped n-BaSi2 epitaxial films by atomic hydrogen passivation Reviewed International journal

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

APPLIED PHYSICS EXPRESS   Vol. 13 ( 5 ) page： .   2020.5

Undoped p-type BaSi2 emitter prepared by thermal evaporation and post-annealing for crystalline silicon heterojunction solar cells Reviewed International journal

Kimura Yuki, Gotoh Kazuhiro, Kurokawa Yasuyoshi, Usami Noritaka

APPLIED PHYSICS EXPRESS   Vol. 13 ( 5 )   2020.5

Scalable fabrication of GaN on amorphous substrates via MOCVD on highly oriented silicon seed layers Reviewed International coauthorship International journal

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

JOURNAL OF CRYSTAL GROWTH   Vol. 535   2020.4

3D visualization of growth interfaces in cast Si ingot using inclusions distribution Reviewed International coauthorship International journal

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

JOURNAL OF CRYSTAL GROWTH   Vol. 535   2020.4

Drastic enhancement of photoresponsivity in C-doped BaSi2 films formed by radio-frequency sputtering Reviewed International journal

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

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 59   2020.4

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

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

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 59   2020.4

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 Reviewed International journal

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   Vol. 59   2020.4

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

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

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 59   2020.4

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

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

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 59   2020.4

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

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

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 59   2020.4

Effects of evaporation vapor composition and post-annealing conditions on carrier density of undoped BaSi2 evaporated films Reviewed International journal

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

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 59   2020.4

Effect of Si substrate modification on improving the crystalline quality, optical and electrical properties of thermally-evaporated BaSi2 thin-films for solar cell applications Reviewed International coauthorship International journal

Mai Thi Kieu Lien, Usami Noritaka

INTERNATIONAL JOURNAL OF MODERN PHYSICS B   Vol. 34 ( 8 )   2020.3

Surface-orientation control of silicon thin films via aluminum-induced crystallization on monocrystalline cubic substrates International coauthorship

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

JOURNAL OF CRYSTAL GROWTH   Vol. 533   2020.3

Effect of hydrogen plasma treatment on the passivation performance of TiOx on crystalline silicon prepared by atomic layer deposition Reviewed International journal

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

JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A   Vol. 38 ( 2 )   2020.3

Effect of forming gas annealing on hydrogen content and surface morphology of titanium oxide coated crystalline silicon heterocontacts Reviewed International journal

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

JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A   Vol. 38 ( 2 )   2020.3

Point defects in BaSi2 thin films for photovoltaic applications studied by positron annihilation spectroscopy International coauthorship

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   Vol. 127 ( 8 )   2020.2

Effect of the Niobium-Doped Titanium Oxide Thickness and Thermal Oxide Layer for Silicon Quantum Dot Solar Cells as a Dopant-Blocking Layer Reviewed International journal

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

NANOSCALE RESEARCH LETTERS   Vol. 15 ( 1 )   2020.2

Work function of indium oxide thin films on p-type hydrogenated amorphous silicon

Semma Masanori, Gotoh Kazuhiro, Kurokawa Yasuyoshi, Usami Noritaka

2020 47TH IEEE PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC)     page： 124 - 127   2020

Structural properties of triple junctions acting as dislocation sources in high-performance Si ingots

Ohno Yutaka, Tajima Kazuya, Kutsukake Kentaro, Usami Noritaka

2020 47TH IEEE PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC)     page： 2340 - 2340   2020

Fabrication of silicon-nanocrystals-embedded silicon oxide passivating contacts

Tsubata Ryohei, Gotoh Kazuhiro, Kurokawa Yasuyoshi, Usami Noritaka

2020 47TH IEEE PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC)     page： 969 - 972   2020

Application of artificial neural network to optimize sensor positions for accurate monitoring: an example with thermocouples in a crystal growth furnace Reviewed International journal

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

APPLIED PHYSICS EXPRESS   Vol. 12 ( 12 )   2019.12

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   Vol. 216 ( 22 )   2019.11

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

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

HYPERFINE INTERACTIONS   Vol. 240 ( 1 )   2019.9

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   Vol. 9 ( 7 )   2019.7

Marked enhancement of the photoresponsivity and minority-carrier lifetime of BaSi2 passivated with atomic hydrogen International coauthorship

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   Vol. 3 ( 6 )   2019.6

Evidence of solute PEDOT:PSS as an efficient passivation material for fabrication of hybrid c-Si solar cells Reviewed International journal

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

SUSTAINABLE ENERGY & FUELS   Vol. 3 ( 6 ) page： 1448 - 1454   2019.6

Impact of size distributions of Ge islands as etching masks for anisotropic etching on formation of anti-reflection structures International coauthorship

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

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 58 ( 4 )   2019.4

Epitaxial growth of SiGe on Si substrate by printing and firing of Al-Ge mixed paste Reviewed International journal

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

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 58 ( 4 )   2019.4

Local Structure of High Performance TiOx Electron-Selective Contact Revealed by Electron Energy Loss Spectroscopy Reviewed

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

ADVANCED MATERIALS INTERFACES   Vol. 6 ( 3 )   2019.2

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

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

APPLIED PHYSICS EXPRESS   Vol. 12 ( 2 )   2019.2

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

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

SOLAR ENERGY MATERIALS AND SOLAR CELLS   Vol. 189   page： 239-244   2019.1

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

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

MRS ADVANCES   Vol. 4 ( 13 ) page： 749 - 754   2019

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

Lee Hyunju, Kamioka Takefumi, Usami Noritaka, Ohshita Yoshio

MRS ADVANCES   Vol. 4 ( 13 ) page： 769-775   2019

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

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

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

Fine Line Al Printing on Narrow Point Contact Opening for Front Side Metallization Reviewed

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)   Vol. 2147   2019

Optimized electrical control of a Si/SiGe spin qubit in the presence of an induced frequency shift Reviewed International coauthorship

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   Vol. 4   2018.10

Application of weighted Voronoi diagrams to analyze nucleation sites of multicrystalline silicon ingots Reviewed

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

JOURNAL OF CRYSTAL GROWTH   Vol. 499   page： 62-66   2018.10

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

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

THIN SOLID FILMS   Vol. 663   page： 14-20   2018.10

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   Vol. 11 ( 10 )   2018.10

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

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

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 57 ( 8 )   2018.8

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   Vol. 57 ( 8 )   2018.8

Influence of barrier layer's height on the performance of Si quantum dot solar cells Reviewed

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

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 57 ( 8 )   2018.8

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   Vol. 57 ( 8 )   2018.8

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   Vol. 57 ( 8 )   2018.8

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   Vol. 57 ( 8 )   2018.8

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   Vol. 491   page： 120-125   2018.6

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   Vol. 8 ( 5 )   2018.5

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   Vol. 57 ( 4 )   2018.4

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   Vol. 76   page： 37-41   2018.3

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   Vol. 76   page： 37 - 41   2018.3

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 ) page： 143-148   2018.3

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   Vol. 75   page： 143 - 148   2018.3

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 ) page： 04FS01   2018.2

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   Vol. 13 ( 2 ) page： 102 - +   2018.2

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   Vol. 3 ( 25 ) page： 1435-1442   2018

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   Vol. 3 ( 25 ) page： 1387-1392   2018

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   Vol. 3 ( 25 ) page： 1419-1426   2018

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)     page： 3896-3899   2018

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)     page： 1871-1873   2018

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)     page： 3097-3101   2018

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)     page： .   2018

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)     page： 2118-2120   2018

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)     page： 2852-2856   2018

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)     page： 1986-1990   2018

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   Vol. 72   page： 93-98   2017.12

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   Vol. 51 ( 12 ) page： 1542 - 1546   2017.12

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 ) page： 127-132   2017.11

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   Vol. 70   page： 127 - 132   2017.11

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   Vol. 32 ( 11 )   2017.11

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 ) page： 93-98   2017.10

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   Vol. 475   page： 186-191   2017.10

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

Hara Kosuke O., Suzuki Shintaro, Usami Noritaka

THIN SOLID FILMS   Vol. 639   page： 7 - 11   2017.10

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 ) page： 114002   2017.9

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   Vol. 636   page： 546-551   2017.8

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

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

Thin Solid Films   ( 639 ) page： 7-11   2017.8

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   Vol. 56 ( 8 )   2017.8

Effect of Surface Morphology Randomness on Optical Properties of Si-based Photonic Nanostructures Reviewed

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

Jpn. J. Appl. Phys.   ( 56 ) page： 08MA02   2017.7

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   Vol. 64   page： 7   2017.7

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   Vol. 64 ( 7 ) page： 2886-2892   2017.7

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   Vol. 56 ( 7 )   2017.7

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

Iwata Taisho, Takahashi Isao, Usami Noritaka

JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 56 ( 7 )   2017.7

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   Vol. 166   page： 39 - 44   2017.7

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 ) page： 546-551   2017.6

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 ) page： 186-191   2017.6

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   Vol. 468   page： 601-604   2017.6

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

Hayama Yusuke, Takahashi Isao, Usami Noritaka

JOURNAL OF CRYSTAL GROWTH   Vol. 468   page： 610 - 613   2017.6

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   Vol. 468   page： 620-624   2017.6

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   Vol. 468   page： 625-629   2017.6

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   Vol. 127   page： 610-613   2017.6

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   Vol. 468   page： 625 - 629   2017.6

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   Vol. 468   page： 601 - 604   2017.6

Towards optimized nucleation control in multicrystalline silicon ingot for solar cells

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

JOURNAL OF CRYSTAL GROWTH   Vol. 468   page： 620 - 624   2017.6

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 ) page： 075502   2017.6

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 ) page： 075501   2017.6

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   Vol. 56 ( 5 )   2017.5

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   Vol. 56 ( 5 )   2017.5

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   Vol. 56 ( 5 )   2017.5

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   Vol. 56 ( 5 )   2017.5

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

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

Jpn. J. Appl. Phys.   ( 56 ) page： 05DB06   2017.4

Postannealing effects on undoped BaSi₂ evaporated films grown on Si substrates Reviewed

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 ) page： 05DB05   2017.4

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

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

Jpn. J. Appl. Phys.   ( 56 ) page： 05DB04   2017.4

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   Vol. 56 ( 4 )   2017.4

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   Vol. 56 ( 4 )   2017.4

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   Vol. 166   page： 39-44   2017.3

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

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

Japanese Journal of Applied Physics   Vol. 56   page： 04CS07   2017.3

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

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

Jpn. J. Appl. Phys.   ( 56 ) page： 05DB01   2017.2

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

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

Japanese Journal of Applied Physics   Vol. 56   page： 04CS01   2017.1

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

Suemasu Takashi, Usami Noritaka

JOURNAL OF PHYSICS D-APPLIED PHYSICS   Vol. 50 ( 2 ) page： 1-18   2017.1

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

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

Journal of Materials Science and Chemical Engineering   Vol. 5   page： 26-34   2017.1

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 ) page： 11202   2017

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 ) page： 11201   2017

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   Vol. 468   page： 625-629   2017

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   Vol. 51 ( 12 ) page： 1542-1546   2017

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   Vol. 124   page： 598-603   2017

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   Vol. 124   page： 734-739   2017

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   Vol. 124   page： 598-603   2017

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)     page： 1765-1768   2017

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)     page： 1794-1796   2017

Numerical simulation and performance optimization of perovskite solar cell

Nanduri Sai Naga Raghuram, Siddiki Mahbube K., Chaudhry Ghulam M., Alharthi Yahya Z.

2017 IEEE 44TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC)     page： 1018 - 1021   2017

Exploring the Potential of Semiconducting BaSi₂ for Thin-Film Solar Cell Applications Reviewed

T. Suemasu and N. Usami

Journal of Physics D: Applied Physics   Vol. 50   page： 023001   2016.11

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   Vol. 616   page： 213-219   2016.10

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.   Vol. 55   page： 091302   2016.8

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

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

Energy Procedia   Vol. 92   page： 801-807   2016.8

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   Vol. 3 ( 7 ) page： 076204   2016.7

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   Vol. 157   page： 393-398   2016.7

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

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

PROGRESS IN PHOTOVOLTAICS: RESEARCH AND APPLICATIONS     2016.5

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   Vol. 108   page： 152101   2016.4

Modulated surface nanostructures for enhanced light trapping and reduced surface reflection of crystalline silicon solar cells Reviewed

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

Japanese Journal of Applied Physics   ( 55 ) page： 52302   2016.4

Simple vacuum evaporation route to BaSi₂ thin films for solar cell applications Reviewed

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

Energy Procedia   Vol. 141   page： 27-31   2016.3

On the mechanism of BaSi₂ thin film formation on Si substrate by vacuum evaporation Reviewed

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

Energy Procedia   Vol. 141   page： 23-26   2016.3

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   Vol. 441   page： 124-130   2016.2

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 ) page： 032303   2016.2

Control of electrical properties of BaSi₂ thin films by alkali-metal doping using alkali-metal fluorides Reviewed

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

Thin Solid Films   Vol. 603   page： 218-223   2016.2

Compressively strained Si/Si₁_xCx heterostructures formed on Ar ion implanted Si(100) substrates Reviewed

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

Japanese Journal of Applied Physics   Vol. 55   page： 031302   2016.2

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 ) page： 774-780   2015.12

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   Vol. 595   page： 68-72   2015.10

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

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

Applied Physics Express   Vol. 8   page： 105501   2015.9

Selective growth of vertical silicon nanowire array guided by anodic aluminum oxide template Reviewed

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

Japanese Journal of Applied Physics   Vol. 54   page： 095003   2015.8

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

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

Japanese Journal of Applied Physics   Vol. 54   page： 08KD11   2015.7

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

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

Japanese Journal of Applied Physics   Vol. 54   page： 08KA06   2015.7

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

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

Japanese Journal of Applied Physics   Vol. 54   page： 08KC03   2015.7

Effect of Anodization Process of Aluminum Oxide Template on Selective Growth of Si Nanowires Reviewed

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

Japanese Journal of Applied Physics   Vol. 54   page： 08KA02   2015.6

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

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

Japanese Journal of Applied Physics   Vol. 54   page： 08KA01   2015.6

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

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

Applied Physics Letters   Vol. 106   page： 222102   2015.6

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 ) page： 095701   2015.3

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

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

Japanese Journal of Applied Physics   Vol. 54   page： 07JE02   2015.3

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   Vol. 54 ( 3 ) page： 030306   2015.3

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

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   Vol. 54   page： 030306   2015.2

Absorption enhancement in nanotextured solar cells with Ge/Si heterostructures

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

Japanese Journal of Applied Physics   ( 54 ) page： 04DR03   2015.1

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

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

INTERNATIONAL JOURNAL OF PHOTOENERGY   ( 2015 ) page： 790242   2015.1

バルク結晶成長のこの10年 Reviewed

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

  Vol. 42 ( 1 ) page： pp.64-68   2015

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

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

Applied Physics Express   Vol. 7   page： 122301   2014.11

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 ) page： 110312   2014.10

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   Vol. 116   page： 123709   2014.9

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 ) page： 726-732   2014.7

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 ) page： 078004   2014.6

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   Vol. 115   page： 223701   2014.6

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   Vol. 115   page： 223701   2014.6

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

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

  ( 115 ) page： 193510   2014.5

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   Vol. 557   page： 368-371   2014.4

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   Vol. 557   page： 338-341   2014.4

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   Vol. 557   page： 147-150   2014.4

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   Vol. 557   page： 143-146   2014.4

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   Vol. 557   page： 90-93   2014.4

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   Vol. 115 ( 9 ) page： 094301   2014.3

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   Vol. 389   page： 112-119   2014.3

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   Vol. 16 ( 13 ) page： 2578-2583   2014.2

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   Vol. 53   page： 04EH03   2014.2

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   Vol. 53   page： 04EH01   2014.2

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

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   Vol. 53   page： 04ER04   2014.2

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   Vol. 22 ( 52 ) page： A225-A232   2014.1

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   Vol. 104 ( 2 ) page： 022106   2014.1

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   Vol. 21   page： 161-164   2014.1

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   Vol. 4 ( 1 ) page： 84-87   2014.1

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 ©   Vol. 10   page： 1781-1784   2013.12

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 ©   Vol. 10   page： 1756-1768   2013.12

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 ©   Vol. 10   page： 1765-1768   2013.12

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 ©   Vol. 10   page： 1769-1772   2013.12

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 ©   Vol. 10   page： 1753-1755   2013.12

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 ©   Vol. 10   page： 1677-1680   2013.11

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   Vol. 6   page： 112302   2013.11

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   Vol. 6 ( 11 ) page： 112302   2013.10

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   Vol. 114   page： 153101   2013.10

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   Vol. 103   page： 142113   2013.9

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

T.Tayagaki, Y.Hoshi, N.Usami

Scientific Reports   Vol. 3   page： 2703   2013.9

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   Vol. 6   page： 025505   2013.9

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   Vol. 378   page： 365-367   2013.9

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   Vol. 378   page： 636-639   2013.9

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   Vol. 378   page： 251-253   2013.9

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   Vol. 378   page： 201-204   2013.9

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   Vol. 378   page： 198-200   2013.9

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   Vol. 378   page： 212-217   2013.9

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   Vol. 378   page： 193-197   2013.9

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   Vol. 2 ( 11 ) page： Q195-Q199   2013.8

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   Vol. 52 ( 8 ) page： UNSP 080202   2013.8

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   Vol. 13 ( 9 ) page： 3908-3912   2013.7

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   Vol. 372   page： 189-192   2013.6

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   Vol. 10   page： 1035-1037   2013.5

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   Vol. 8   page： 228   2013.5

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   Vol. 534   page： 470-473   2013.5

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   Vol. 113 ( 13 ) page： 133503   2013.4

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   Vol. 13 ( 4 ) page： 1767-1770   2013.4

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   Vol. 102 ( 11 ) page： 112107   2013.3

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   Vol. 113 ( 5 )   2013.2

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   Vol. 6 ( 2 )   2013.2

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   Vol. 362   page： 16-19   2013.1

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   Vol. 24 ( 1 )   2013.1

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   Vol. 102 ( 1 )   2013.1

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   Vol. 362   page： 276-281   2013.1

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   Vol. 103   page： 142113   2013

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   Vol. 114 ( 15 ) page： 153101   2013

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   Vol. 18 ( 6 ) page： 1830-1838   2012.12

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   Vol. 51 ( 10 )   2012.10

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   Vol. 356   page： 65-69   2012.10

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   Vol. 51 ( 10 )   2012.10

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   Vol. 51 ( 10 )   2012.10

Growth velocity and grain size of multicrystalline solar cell silicon

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

Journal of Crystal Growth   Vol. 356   page： 17-21   2012.10

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   Vol. 112 ( 8 )   2012.10

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   Vol. 51 ( 9 )   2012.9

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   Vol. 101 ( 13 )   2012.9

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   Vol. 51 ( 9 )   2012.9

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   Vol. 101 ( 7 )   2012.8

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   Vol. 101 ( 6 )   2012.8

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   Vol. 20 ( 13 ) page： 14714-14721   2012.6

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   Vol. 348 ( 1 ) page： 75-79   2012.6

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   Vol. 23 ( 18 )   2012.5

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   Vol. 5 ( 5 )   2012.5

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   Vol. 100 ( 22 )   2012.5

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   Vol. 345 ( 1 ) page： 16-21   2012.4

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   Vol. 344 ( 1 )   2012.4

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   Vol. 51 ( 4 )   2012.4

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   Vol. 100 ( 15 )   2012.4

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   Vol. 51 ( 4 )   2012.4

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   Vol. 50 ( 12 )   2011.12

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   Vol. 12   page： S187-S192   2011.11

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   Vol. 110 ( 8 )   2011.10

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   Vol. 65 ( 6 ) page： 556-559   2011.9

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   Vol. 4 ( 9 )   2011.9

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   Vol. 12 ( 3 )   2011.6

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   Vol. 109 ( 8 )   2011.4

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   Vol. 88   page： 465-468   2011.4

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   Vol. 50 ( 4 )   2011.4

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   Vol. 109 ( 3 )   2011.2

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   Vol. 312 ( 24 ) page： 3670-3674   2010.12

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   Vol. 22 ( 47 )   2010.12

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   Vol. 312 ( 22 ) page： 3257-3260   2010.11

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   Vol. 97 ( 21 )   2010.11

Room-temperature electroluminescence from Si microdisks with Ge quantum dots

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

Optics Express   Vol. 18 ( 13 ) page： 13945-13950   2010.6

Growth mechanism of the Si < 110 > faceted dendrite

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

Physical Review B   Vol. 81 ( 22 )   2010.6

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   Vol. 312 ( 7 ) page： 897-901   2010.3

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   Vol. 107 ( 10 )   2010.3

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   Vol. 96 ( 9 )   2010.3

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   Vol. 518 ( 9 ) page： 2454-2457   2010.2

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   Vol. 107 ( 1 )   2010.1

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   Vol. 518   page： S162-S164   2010.1

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   Vol. 49 ( 4 )   2010

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   Vol. 3 ( 2 )   2010

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   Vol. 49 ( 4 )   2010

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   Vol. 49   2010

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   Vol. 3 ( 9 )   2010

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   Vol. 312 ( 1 ) page： 19-23   2009.12

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   Vol. 80 ( 17 )   2009.11

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   Vol. 48 ( 11 )   2009.11

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   Vol. 53 ( 10 ) page： 1135-1143   2009.10

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   Vol. 95   2009.9

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   Vol. 311 ( 14 ) page： 3581-3586   2009.7

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   Vol. 57 ( 11 ) page： 3268-3276   2009.6

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   Vol. 2 ( 5 )   2009.5

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   Vol. 48 ( 2 )   2009.2

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   Vol. 105 ( 4 )   2009.2

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   Vol. 311 ( 2 ) page： 228-231   2009.1

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   Vol. 311   page： 883-887   2009

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   Vol. 311 ( 3 ) page： 806-808   2009

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   Vol. 311 ( 3 ) page： 825-828   2009

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   Vol. 311   page： 819-824   2009

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   Vol. 311   page： 809-813   2009

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   Vol. 311   page： 814-818   2009

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   Vol. 310 ( 24 ) page： 5248-5251   2008.12

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   Vol. 47 ( 12 ) page： 8790-8792   2008.12

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   Vol. 1 ( 12 )   2008.12

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   Vol. 517 ( 1 ) page： 125-127   2008.11

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   Vol. 517 ( 1 ) page： 14-16   2008.11

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   Vol. 517 ( 1 ) page： 254-256   2008.11

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   Vol. 517 ( 1 ) page： 235-238   2008.11

Vacancy formation during oxidation of silicon crystal surface

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

Applied Physics Letters   Vol. 93 ( 10 )   2008.9

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   Vol. 1 ( 8 )   2008.8

Growth mechanism of Si-faceted dendrites

K. Fujiwara, K. Maeda, N. Usami and K. Nakajima

Physical Review Letters   Vol. 101 ( 5 )   2008.8

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   Vol. 1 ( 7 )   2008.7

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   Vol. 47 ( 6 ) page： 4630-4633   2008.6

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   Vol. 56 ( 11 ) page： 2663-2668   2008.6

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   Vol. 1 ( 1 )   2008.1

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   Vol. 40 ( 6 ) page： 2122-2124   2008

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   Vol. 516 ( 5 ) page： 600-603   2008

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.   Vol. 47   page： 2927-2931   2008

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   Vol. 102 ( 10 )   2007.11

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   Vol. 46 ( 11 ) page： 7198-7203   2007.11

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   Vol. 91 ( 1 )   2007.7

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   Vol. 91   2007.7

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   Vol. 57 ( 2 ) page： 81-84   2007.7

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   Vol. 90 ( 18 )   2007.4

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   Vol. 101 ( 5 )   2007.3

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   Vol. 101 ( 6 )   2007.3

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   Vol. 7 ( 2 ) page： 439-444   2007.2

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   Vol. 48 ( 2 ) page： 143-147   2007.2

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   Vol. 91   page： 123-128   2007.1