直接遷移／間接遷移ハイブリッド型超格子を用いた薄膜太陽電池の研究

• Project/Area Number: 25420298
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Electronic materials/Electric materials
• Research Institution: Waseda University
• Principal Investigator: 河原塚 篤 早稲田大学, 理工学術院, 准教授 (40329082)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Project Status: Discontinued (Fiscal Year 2014)
• Budget Amount: ¥5,330,000 (Direct Cost: ¥4,100,000、Indirect Cost: ¥1,230,000); Fiscal Year 2015: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2014: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2013: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000)
• Keywords: 太陽電池 / 直接遷移 / 間接遷移 / 超格子 / AlAs / GaAs / 電流電圧特性 / 再結合電流 / InAs / 混晶

Outline of Annual Research Achievements

本年度は、直接遷移／間接遷移ハイブリッド型太陽電池の特性評価に不可欠な、電流電圧(I-V)特性の評価手法に関する研究を行った。具体的には、間接遷移型の伝導特性を明らかにする上でキーとなる再結合電流の評価手法を開発し、実際にAlGaAs/GaAs超格子太陽電池に適用し特性の解析を行った。
太陽電池のI-V特性は生成電流と注入電流からなり、注入電流は更に拡散電流成分と再結合電流成分の和で与えられる。本研究で開発した手法の大きな特徴は、一般的に特性値として与えられる形状因子(FF)、開放電圧(Voc)、短絡電流(Isc)の三つの値のみから、外部量子効率(ts)、および拡散電流成分の飽和電流密度(J1)および再結合電流成分の飽和電流密度(J2)を決定できることにある。この手法の大きな利点は、I-V特性およびデバイス構造の詳細を知ること無しに、一般的に特性値として与えられる形状因子、開放電圧、短絡電流の三つの値のみから拡散電流と再結合電流のバイアス依存性を評価できる点にあり、簡便かつ汎用性の広い手法である。
実際に製作した、GaAsバルク、AlGaAs/GaAs超格子活性層からなるPIN接合太陽電池の特性値を用いて評価したところ、バルクではts=84%、J1=2.1E(-16) mA/cm2、J2=5.6E(-8) mA/cm2、超格子ではts=83%、J1=3.5E(-18) mA/cm2、J2=1.4E(-8) mA/cm^2とすると実験値を良く再現する。バルク、超格子いずれも、再結合成分が拡散成分に比べはるかに大く最大出力点において92%、98%とに達することが明らかになった。この結果は結晶品質の向上による非発光再結合の抑制とともに、直接／間接ハイブリッド構造の導入による伝導特性の改善が薄膜太陽電池の効率向上につながることを示している。

Research Products

• [Journal Article] Recombination current in AlGaAs/GaAs superlattice solar-cells grown by molecular beam epitaxy (2015)
  • Author(s): A. Kawaharazuka, J. Nishinaga, Y. Horikoshi
  • Journal Title: Journal of Crystal Growth Volume: in press Pages: 326-329
  • DOI: 10.1016/j.jcrysgro.2015.03.047
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Effects of surface barrier layer in AlGaAs/GaAs solar cells (2015)
  • Author(s): Hiroyuki Urabe, Makoto Kuramoto, Tomohiro Nakano, Atsushi Kawaharazuka, Toshiki Makimoto, Yoshiji Horikoshi
  • Journal Title: Journal of Crystal Growth Volume: in press Pages: 330-332
  • DOI: 10.1016/j.jcrysgro.2015.02.097
  • Peer Reviewed
• [Journal Article] Optical properties of AlxGa1−xAs/GaAs superlattice solar cells (2015)
  • Author(s): Makoto Kuramoto, Hiroyuki Urabe, Tomohiro Nakano, Atsushi Kawaharazuka, Jiro Nishinaga, Toshiki Makimoto, Yoshiji Horikoshi
  • Journal Title: Journal of Crystal Growth Volume: in press Pages: 333-336
  • DOI: 10.1016/j.jcrysgro.2015.03.024
  • Peer Reviewed
• [Journal Article] Study of single crystal CuInSe2 thin films and CuGaSe2/CuInSe2 single quantum well grown by molecular beam epitaxy (2015)
  • Author(s): Sathiabama Thiru, Masaki Asakawa, Kazuki Honda, Atsushi Kawaharazuka, Atsushi Tackeuchi, Toshiki Makimoto, Yoshiji Horikoshi
  • Journal Title: Journal of Crystal Growth Volume: in press
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] High absorption efficiency of AlGaAs/GaAs superlattice solar cells (2015)
  • Author(s): Jiro Nishinaga, Atsushi Kawaharazuka and Yoshiji Horikoshi
  • Journal Title: Japanese Journal of Applied Physics Volume: 54 Issue: 5 Pages: 052301-052301
  • DOI: 10.7567/jjap.54.052301
  • NAID: 210000145127
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Investigation of CuGaSe2/CuInSe2 double heterojunction interfaces grown by molecular beam epitaxy (2015)
  • Author(s): Sathiabama Thiru, Masaki Asakawa, Kazuki Honda, Atsushi Kawaharazuka, Atsushi Tackeuchi, Toshiki Makimoto and Yoshiji Horikoshi
  • Journal Title: AIP Advances Volume: 5 Issue: 2 Pages: 027120-027120
  • DOI: 10.1063/1.4908229
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] High Absorption Efficiency Superlattice Solar Cells by Excitons (2013)
  • Author(s): J. Nishinaga, A. Kawaharazuka, K. Onomitsu, and Y. Horikoshi
  • Journal Title: J. Appl. Phys. 52 Volume: 52 Issue: 11R Pages: 112302-112302
  • DOI: 10.7567/jjap.52.112302
  • NAID: 40019883484
  • Peer Reviewed
• [Journal Article] Characteristics of CuGaSe2 layers grown on GaAs substrates (2013)
  • Author(s): M.Fujita, A. Kawaharazuka, and Y. Horikoshi
  • Journal Title: J. Cryst. Growth Volume: 378 Pages: 154-157
  • DOI: 10.1016/j.jcrysgro.2012.12.171
  • Peer Reviewed
• [Journal Article] Photoluminescence study of Si doped and undoped Chalcopyrite CuGaSe2 (2013)
  • Author(s): S. Thiru, M. Fujita, A. Kawaharazuka, and Y. Horikoshi
  • Journal Title: Appl. Phys. A Volume: 113 Issue: 2 Pages: 257-261
  • DOI: 10.1007/s00339-013-7951-5
  • Peer Reviewed
• [Presentation] GaAs(111)B面上のGaの挙動 (2014)
  • Author(s): 河原塚篤，堀越佳治
  • Organizer: 第75回応用物理学会秋季学術講演会
  • Place of Presentation: 北海道大学
  • Year and Date: 2014-09-17 – 2014-09-20
• [Presentation] AlGaAs/GaAs太陽電池における表面再結合制御 (2014)
  • Author(s): 浦部宏之，倉本真，中野朋洋，河原塚篤，牧本俊樹，堀越佳治
  • Organizer: 第75回応用物理学会秋季学術講演会
  • Place of Presentation: 北海道大学
  • Year and Date: 2014-09-17 – 2014-09-20
• [Presentation] AlxGa1-xAs/GaAs超格子太陽電池における障壁層厚さの効果 (2014)
  • Author(s): 倉本真，浦部宏之，中野朋洋，河原塚篤，西永慈郎，牧本俊樹，堀越佳治
  • Organizer: 第75回応用物理学会秋季学術講演会
  • Place of Presentation: 北海道大学
  • Year and Date: 2014-09-17 – 2014-09-20
• [Presentation] AlGaAs/GaAs超格子pin接合における発光特性の検討 (2014)
  • Author(s): 中野朋洋，浦部宏之，倉本真，河原塚篤，西永慈郎，小野満恒二，牧本俊樹， 堀越佳治
  • Organizer: 第75回応用物理学会秋季学術講演会
  • Place of Presentation: 北海道大学
  • Year and Date: 2014-09-17 – 2014-09-20
• [Presentation] Recombination Current in AlGaAs/GaAs Superlattice Solar-cells Grown by Molecular Beam Epitaxy (2014)
  • Author(s): A. Kawaharazuka, J. Nishinaga, and Y. Horikoshi
  • Organizer: 18th International Conference on Molecular Beam Epitaxy
  • Place of Presentation: Flagstaff, Arizona, USA
  • Year and Date: 2014-09-07 – 2014-09-12
• [Presentation] Effects of surface barrier layer in AlGaAs/GaAs solar cells (2014)
  • Author(s): H. Urabe, M. Kuramoto, T. Nakano, A. Kawaharazuka, T. Makimoto, and Y. Horikoshi
  • Organizer: 18th International Conference on Molecular Beam Epitaxy
  • Place of Presentation: Flagstaff, Arizona, USA
  • Year and Date: 2014-09-07 – 2014-09-12
• [Presentation] Optical Properties of AlxGa1-xAs/GaAs Superlattice Solar Cells (2014)
  • Author(s): M. Kuramoto, H. Urabe, T. Nakano, A. Kawaharazuka, J. Nishinaga, T. Makimoto, and Y. Horikoshi
  • Organizer: 18th International Conference on Molecular Beam Epitaxy
  • Place of Presentation: Flagstaff, Arizona, USA
  • Year and Date: 2014-09-07 – 2014-09-12
• [Presentation] RHEED Observation and X-ray Diffraction of CuInSe2/(CuGaSe2:Ge) Hetero-structure grown on GaAs(001) (2014)
  • Author(s): S. Thiru, A. Kawaharazuka, and Y. Horikoshi
  • Organizer: 18th International Conference on Molecular Beam Epitaxy
  • Place of Presentation: Flagstaff, Arizona, USA
  • Year and Date: 2014-09-07 – 2014-09-12
• [Presentation] 太陽電池の特性値を用いた再結合電流の評価 (2014)
  • Author(s): 河原塚篤、西永慈郎、堀越佳治
  • Organizer: 第６１回応用物理学会春季学術講演会
  • Place of Presentation: 青山学院大学
• [Presentation] GaAs(001)上に成長したCuGaSe2薄膜のRHEED観察と光学特性 (2014)
  • Author(s): SathiabamaThiru、佐藤知嵩、豊田康揮、河原塚篤、堀越佳治
  • Organizer: 第６１回応用物理学会春季学術講演会
  • Place of Presentation: 青山学院大学
• [Presentation] AlGaAs/GaAs超格子太陽電池における励起子閉じ込め効果 (2014)
  • Author(s): 倉本真、中野朋洋、浦部宏之、堀越佳治、河原塚篤、西永慈郎
  • Organizer: 第６１回応用物理学会春季学術講演会
  • Place of Presentation: 青山学院大学
• [Presentation] 高温時におけるAlGaAs/GaAs超格子太陽電池のI-V特性 (2014)
  • Author(s): 西永慈郎、河原塚篤、堀越佳治
  • Organizer: 第６１回応用物理学会春季学術講演会
  • Place of Presentation: 青山学院大学
• [Presentation] Effect of excitonic absorption on the efficiency of AlGaAs/GaAs solar cells (2013)
  • Author(s): Y. Horikoshi, J. Nishinaga, A. Kawaharazuka, K. H. Ploog, K. Onomitsu, and M. Fujita
  • Organizer: 2013 JSAP-MRS Joint Symposia
  • Place of Presentation: Kyoto
  • Invited
• [Presentation] Excitonic absorption on AlGaAs/GaAs superlattice solar cells (2013)
  • Author(s): J. Nishinaga, A. Kawaharazuka, K. Onomitsu, K. Ploog, and Y. Horikoshi
  • Organizer: 40th International Symposium on Compound Semiconductors
  • Place of Presentation: Kobe
• [Presentation] Si/SiOx Superlattice Growth by Molecular Beam Epitaxy (2013)
  • Author(s): M. Fujita, T. Kitada, M. Kondoh, A. Kawarahazuka, Y. Horikoshi
  • Organizer: 30th North American Molecular Beam Epitaxy Conference
  • Place of Presentation: Banff, Canada
• [Presentation] Photoluminescence of single crystal thin film chalcopyrite CuGaSe2 grown on GaAs(001) (2013)
  • Author(s): S. Thiru, M. Fujita, A. Kawaharazuka, K. Onomitsu, and Y. Horikoshi
  • Organizer: 40th International Symposium on Compound Semiconductors
  • Place of Presentation: Kobe
• [Presentation] Excitonic absorption on AlGaAs/GaAs superlattice solar cells (2013)
  • Author(s): J. Nishinaga, A. Kawaharazuka, and Y. Horikoshi
  • Organizer: 30th North American Molecular Beam Epitaxy Conference
  • Place of Presentation: Banff, Canada
• [Presentation] Excitonic absorption on AlGaAs/GaAs superlattice solar cells (2013)
  • Author(s): J. Nishinaga, A. Kawaharazuka, and Y. Horikoshi
  • Organizer: 2013 MRS Fall Meeting
  • Place of Presentation: Boston, Massachusetts, USA
• [Presentation] AlGaAs/GaAs超格子太陽電池における励起子吸収 (2013)
  • Author(s): 西永慈郎、河原塚篤、小野満恒二、K.H. Ploog、堀越佳治
  • Organizer: 第７４回応用物理学会秋季学術講演会
  • Place of Presentation: 同志社大学