Development of high conversion efficiency silicon solar cells with silicon nanowire surface

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K03498
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 13020:Semiconductors, optical properties of condensed matter and atomic physics-related
• Research Institution: University of Hyogo
• Principal Investigator: Yoshida Haruhiko 兵庫県立大学, 工学研究科, 准教授 (90264837)
• Co-Investigator(Kenkyū-buntansha): 森 英喜 兵庫県立大学, 工学研究科, 助教 (50364039)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: シリコン系太陽電池 / シリコンナノワイヤ / 表面反射率 / キャリアライフタイム / パッシベーション / 界面特性

Outline of Final Research Achievements

Si nanowires fabricated on Si substrates were applied as a method to suppress the optical reflection at the Si surface. Moreover, it has been expected that the solar cell with Si nanowire surface is able to utilize light of the shorter wavelength. However, a further study on the optical and electrical properties of the Si nanowires is necessary for the practical use.
In this study, the reflectance and the minority carrier lifetime of the Si nanowires with various lengths on Si substrates were characterized and optimized. Also, it has been proved that a gallium oxide is effective as a novel passivation film for Si solar cells.

Free Research Field

半導体光学

Academic Significance and Societal Importance of the Research Achievements

結晶系シリコン太陽電池の更なる変換効率向上のためには、キャリア再結合(電気のもととなる電子の消失)及び入射光の反射の抑制が重要となる。さらに、次世代太陽電池としては結晶系シリコン太陽電池の変換効率の限界を超える新しい太陽電池の構造の開発が望まれている。
本課題で得られた光の反射率及びキャリア再結合のシリコンナノワイヤ長依存性や新しい太陽電池用のパッシベーション(保護)膜に関する知見は次世代太陽電池の開発に貢献できるものであると考えられる。