Properties of ultralow reflectance Si formed by surface structure chemical transfer method

• Project/Area Number: 15H01997
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Nanostructural physics
• Research Institution: Osaka University
• Principal Investigator: Kobayashi Hikaru 大阪大学, 産業科学研究所, 教授 (90195800)
• Co-Investigator(Kenkyū-buntansha): 松本 健俊 大阪大学, 産業科学研究所, 准教授 (20390643) ; 今村 健太郎 大阪大学, 産業科学研究所, 助教 (60591302)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥42,380,000 (Direct Cost: ¥32,600,000、Indirect Cost: ¥9,780,000); Fiscal Year 2017: ¥8,060,000 (Direct Cost: ¥6,200,000、Indirect Cost: ¥1,860,000); Fiscal Year 2016: ¥9,230,000 (Direct Cost: ¥7,100,000、Indirect Cost: ¥2,130,000); Fiscal Year 2015: ¥25,090,000 (Direct Cost: ¥19,300,000、Indirect Cost: ¥5,790,000)
• Keywords: シリコンナノクリスタル層 / 屈折率勾配 / 太陽電池 / graded band-gap構造 / ナノ材料 / 表面・界面物性 / 表面パッシベーション / 反射率 / 結晶シリコン / シリコンナノクリスタル / ネットワーク構造 / 屈折率 / 化学的転写法 / 傾斜構造 / マイクロ、ナノデバイス / 傾斜材料

Outline of Final Research Achievements

The valence band energy of a nanocrsytalline Si layer shows a downward shift with the surface structure chemical transfer treatment time, and the energy shift reaches ~0.4eV at maximum. The conduction band energy, on the other hand, is shifted upward by ~0.2eV at maximum. The conduction band of the nanocrystalline Si layer after formation of pn-junction is almost flat. These results show that the nanocrystalline Si layer possesses the grade band-gap structure, leading to effective separation of photo-generated electron hole pairs in the nanocrystalline Si layer, and thus preventing surface recombination.

Research Products

• [Int'l Joint Research] スロバキア科学アカデミー(スロバキア)
• [Int'l Joint Research] Zilina大学(スロバキア)
• [Int'l Joint Research] Ｓｌｏｖａｃ Academy of Science/Zilina University(スロバキア)
• [Journal Article] Improvement of conversion efficiency of silicon solar cells by submicron-textured rear reflector obtained by metal-assisted chemical etching (2017)
  • Author(s): D. Irishika, Y. Onitsuka, K. Imamura, and H. Kobayashi
  • Journal Title: Solar RRL Volume: １ Issue: 7
  • DOI: 10.1002/solr.201700061
  • Peer Reviewed
• [Journal Article] Surface nanocrystalline Si structure for highly efficient crystalline Si solar cells (2017)
  • Author(s): K. Imamura, D. Irishika, and H. Kobayashi
  • Journal Title: Prog. Photovolt. Volume: 25 Issue: 5 Pages: 358-366
  • DOI: 10.1002/pip.2867
  • Peer Reviewed
• [Journal Article] Mechanism of ultra-low reflectivity for nanocrystalline Si/crystalline Si structure formed by surface structure chemical transfer method (2017)
  • Author(s): K. Imamura, D. Irishika, and H. Kobayashi
  • Journal Title: J. Appl. Phys. Volume: 121 Issue: 1
  • DOI: 10.1063/1.4973531
  • Peer Reviewed
• [Journal Article] ight trapping of crystalline Si solar cells by use of nanocrystalline Si layer plus pyramidal texture (2017)
  • Author(s): K. Imamura, T. Nonaka, Y. Onitsuka, D. Irishika, H. Kobayashi
  • Journal Title: Applied Surface Science Volume: 395 Pages: 50-55
  • DOI: 10.1016/j.apsusc.2016.04.132
  • Peer Reviewed
• [Journal Article] Regarding the optical properties of porous layers prepared on Si substrates (2017)
  • Author(s): E. Pincik, R. Brunner, H. Kobayashi, P. Vojtek, Z. Zabudla, M. Mikula, J. Gregus and M. Kucera
  • Journal Title: J. Energy Power Eng. Volume: 11 Issue: 11 Pages: 687-692
  • DOI: 10.17265/1934-8975/2017.11.002
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] About complex refractive index of black Si (2017)
  • Author(s): E. Pincik, R. Brunner, H. Kobayashi, and M. Mikula
  • Journal Title: J. Elect. Eng. Volume: 68 Issue: 7 Pages: 81-83
  • DOI: 10.1515/jee-2017-0063
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Properties of nanocrystalline Si layers embedded in structure of solar cell (2017)
  • Author(s): S. Jurecka, K. Imamura, T. Matsumoto, and H. Kobayashi
  • Journal Title: J. Elect. Eng. Volume: 68 Issue: 7 Pages: 48-52
  • DOI: 10.1515/jee-2017-0055
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Investigation of deep defects in nanocrystalline-Si/Si interfaces using acoustic spectroscopy (2017)
  • Author(s): P. Bury, S. Hardon, H. Kobayashi, and K. Imamura
  • Journal Title: J. Elect. Eng. Volume: 68 Issue: 7 Pages: 43-47
  • DOI: 10.1515/jee-2017-0054
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Multifractal analysis and optical properties of nanostructured silicon layers (2017)
  • Author(s): S. Jurecka, T. Matsumoto, K. Imamura, H. Kobayashi
  • Journal Title: Applied Surface Science Volume: 395 Pages: 150-156
  • DOI: 10.1016/j.apsusc.2016.04.059
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] About the optical properties of oxidized black silicon structures (2017)
  • Author(s): E. Pincik, R. Brunner, H. Kobayashi, M. Mikula, M. Kucera, P. Svec Jr., J. Gregus;, P. Vojtek, Z. Zabria, K. Imamura, M. Zahoran
  • Journal Title: Applied Surface Science Volume: 395 Pages: 185-194
  • DOI: 10.1016/j.apsusc.2016.05.035
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Ultrathin SiO2 layer formed by the nitric acid oxidation of Si (NAOS) method to improve the thermal-SiO2/Si interface for crystalline Si solar cells (2017)
  • Author(s): T. Matsumoto, H. Nakajima, D. Irishika, T. Nonaka, K. Imamura, H. Kobayashi
  • Journal Title: Applied Surface Science Volume: 395 Pages: 56-60
  • DOI: 10.1016/j.apsusc.2016.06.001
  • Peer Reviewed
• [Journal Article] The photoluminescence of multicolor silicon (2016)
  • Author(s): E. Pincik, R. Brunner, H. Kobayashi, M. Mikula, P. Vojtek, J. Gregus, Z. Zabudla, K. Imamura, P. Svec, Jr.
  • Journal Title: J. Chin. Adv. Mater. Soc. Volume: in press Issue: 2 Pages: 158-171
  • DOI: 10.1080/22243682.2016.1151374
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Ultralow Reflectivity and Light Trapping for Crystalline Si Solar Cells by Use of Surface Structure Chemical Transfer Method on Pyramidal Textured Surfaces (2015)
  • Author(s): K. Imamura, T. Nonaka, D. Irishika, H. Kobayashi
  • Journal Title: ECS Solid State Lett. Volume: 4 Issue: 12 Pages: Q63-Q65
  • DOI: 10.1149/2.0091512ssl
  • Peer Reviewed
• [Journal Article] Ultralow reflectivity surfaces by formation of nanocrystalline Si layer for crystalline Si solar cells (2015)
  • Author(s): D. Irishika, K. Imamura, H. Kobayashi
  • Journal Title: Sol. Energ. Mat. Sol. C. Volume: 141 Pages: 1-6
  • DOI: 10.1016/j.solmat.2015.06.005
  • Peer Reviewed
• [Presentation] High conversion efficiency black Si solar cells formed by use of surface structure chemical transfer (SSCT) method (2017)
  • Author(s): Hikaru Kobayashi
  • Organizer: Progress in Applied Surface, Interface and Thin Film Science 2017 (SURFINT-SREN V)
  • Int'l Joint Research / Invited
• [Presentation] Achievement of 20% conversion efficiency from simple structure crystalline Si solar cells fabricated by use of surface structure chemical transfer method (2017)
  • Author(s): Hikaru Kobayashi
  • Organizer: Taiwan Vacuum Society 2017 (TVS-2017)
  • Int'l Joint Research / Invited
• [Presentation] Highly efficient black Si solar cells fabricated by use of surface structure chemical transfer method (2017)
  • Author(s): Hikaru Kobayashi
  • Organizer: Collaborative Conference on Materials Research (CCMR 2017), International Convention Center (ICC)
  • Int'l Joint Research / Invited
• [Presentation] Fabrication and application of Si nanocrystals and nanopowder for energy devices (2017)
  • Author(s): Hikaru Kobayashi
  • Organizer: EMN Meeting on Surface and interface
  • Int'l Joint Research / Invited
• [Presentation] 電気化学的手法による4H-SiC基板の超平坦化とそのメカニズム (2016)
  • Author(s): 赤井智喜，今村健太郎，小林光
  • Organizer: 第36回表面科学学術講演会
  • Place of Presentation: 名古屋国際会議場（愛知県・名古屋市）
  • Year and Date: 2016-11-29
• [Presentation] 化学的転写法により形成した極低反射Si表面の光学特性と、高効率太陽電池への応用 (2016)
  • Author(s): 今村健太郎，入鹿大地，鬼塚裕也，小林光
  • Organizer: 第63回応用物理学会春季学術講演会
  • Place of Presentation: 東京工業大学大岡山キャンパス(東京都)
  • Year and Date: 2016-03-19
• [Presentation] 化学的転写法による極低反射表面と裏面ナノ構造を用いた結晶Si太陽電池の変換効率向上 (2016)
  • Author(s): 鬼塚裕也，入鹿大地，今村健太郎，小林光
  • Organizer: 第63回応用物理学会春季学術講演会
  • Place of Presentation: 東京工業大学大岡山キャンパス(東京都)
  • Year and Date: 2016-03-19
• [Presentation] Ultra-low reflectivity surfaces with nano-structured Si layer (2015)
  • Author(s): Y. Onitsuka, K. Imamura, H. Kobayashi
  • Organizer: The 19th SANKEN International Symposium, The 14th SANKEN Nanotechnology International Symposium
  • Place of Presentation: 大阪大学吹田キャンパス(大阪府、吹田市)
  • Year and Date: 2015-12-07
  • Int'l Joint Research
• [Presentation] Ulta-low reflectivity polycrystalline Si surfaces by formation of nanocrystalline Si layer and achievement of high efficiency crystalline Si solar cells (2015)
  • Author(s): D. Irishika, K. Imamura, H. Kobayashi
  • Organizer: The 19th SANKEN International Symposium, The 14th SANKEN Nanotechnology International Symposium
  • Place of Presentation: 大阪大学吹田キャンパス(大阪府、吹田市)
  • Year and Date: 2015-12-07
  • Int'l Joint Research
• [Presentation] Si surface control for achieving high conversion efficiencies of crystalline Si solar cells (2015)
  • Author(s): H. Kobayashi, D. Irishika, T. Nonaka, K. Imamura
  • Organizer: Progress in applied surface, interface and thin film science 2015
  • Place of Presentation: Italy
  • Year and Date: 2015-11-23
  • Int'l Joint Research / Invited
• [Presentation] 18.9% efficiency crystalline Si solar cells with simple structure fabricated by surface (2015)
  • Author(s): H. Kobayashi
  • Organizer: ACTSEA-2015
  • Place of Presentation: Taiwan
  • Year and Date: 2015-11-08
  • Int'l Joint Research / Invited
• [Presentation] 化学的転写法により形成した極低反射率をもつSiナノクリスタル層/Si構造の光学特性 (2015)
  • Author(s): 今村健太郎，入鹿大地，野中啓章，小林光
  • Organizer: 日本物理学会2015年秋季大会
  • Place of Presentation: 関西大学千里山キャンパス(大阪府、吹田市)
  • Year and Date: 2015-09-16
• [Presentation] 化学的転写法で作製したナノクリスタルSi層に対する表面パッシベーションと結晶Si太陽電池の高効率化 (2015)
  • Author(s): 野中啓章，入鹿大地，今村 健太郎，小林 光
  • Organizer: 第76回応用物理学会秋季学術講演会
  • Place of Presentation: 名古屋国際会議場(愛知県、名古屋市)
  • Year and Date: 2015-09-13
• [Presentation] Ultra‐low reflectivity crystalline Si surfaces fabricated by use of SSCT method and application to high efficiency Si solar cells (2015)
  • Author(s): K. Imamura, D. Irishika, T. Nonaka, H. Kobayashi
  • Organizer: 1st International Conference on Applied Surface Science
  • Place of Presentation: China
  • Year and Date: 2015-07-27
  • Int'l Joint Research
• [Presentation] Ultralow reflectivity crystalline Si surfaces by formation of nanocrystalline Si layer and application to polycrystalline Si solar cells (2015)
  • Author(s): D. Irishika, K. Imamura, H. Kobayashi
  • Organizer: 1st International Conference on Applied Surface Science
  • Place of Presentation: China
  • Year and Date: 2015-07-27
  • Int'l Joint Research
• [Presentation] Fabrication of ultra‐low reflectivity Si solar cells with light trapping effect to achieve a high conversion efficiency (2015)
  • Author(s): T. Nonaka, D. Irishika, K. Imamura, H. Kobayashi
  • Organizer: 1st International Conference on Applied Surface Science
  • Place of Presentation: China
  • Year and Date: 2015-07-27
  • Int'l Joint Research
• [Presentation] Chemical methods for improvement of performance of crystalline Si solar cells (2015)
  • Author(s): H. Kobayashi
  • Organizer: 2015 Symposium for Eco Multi-Functional Nano Materials & ISO/TC 107 Workshop
  • Place of Presentation: Korea
  • Year and Date: 2015-05-15
  • Int'l Joint Research / Invited
• [Presentation] Improvement of crystalline solar cell characteristics by formation of ultralow reflectivity surface using surface structure chemical transfer method (2015)
  • Author(s): H. Kobayashi
  • Organizer: The 5th Asia-Africa Sustainable Energy Forum and Jointly with 7th International Workshop on Sahara Solar Breeder
  • Place of Presentation: 筑波大学筑波キャンパス(茨城県、つくば市)
  • Year and Date: 2015-05-13
  • Int'l Joint Research / Invited
• [Remarks] 大阪大学 産業科学研究所 小林研究室
  • URL: http://www.sanken.osaka-u.ac.jp/labs/fcm/index.html
• [Remarks] シリコン太陽電池の研究
  • URL: http://www.sanken.osaka-u.ac.jp/labs/fcm/research-PV.html