Development of Peelable and Coupleable Absorber with Optimum Bandgap for Tandem Solar Cells

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K14780
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 21050:Electric and electronic materials-related
• Research Institution: Ritsumeikan University
• Principal Investigator: Nishimura Takahito 立命館大学, 立命館グローバル・イノベーション研究機構, 助教 (80822840)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 多接合型太陽電池 / 化合物半導体 / カルコパイライト / 二次元層状物質 / ファンデルワールス力 / 界面密着性 / 剥離技術 / 固液界面

Outline of Final Research Achievements

A crystal growth technique was developed for the fabrication of the high-quality Cu(In,Ga)Se2(CIGSe) top-sell absorber. The flux growth through the Cu-Se liquid phase under Cu-rich conditions led to an increase in the grain size of CIGSe. A supply of the Se element during the growth of the CIGSe with the Cu(2-x)Se precursor resulted in the formation of a uniform Cu-deficient layer on the CIGSe surface. To avoid thermal degradation of the bottom-cell due to deposition temperatures of approximately 600°C, a peeling-off technique using MoSe2 layered material was developed. A semitransparent CIGSe top-cell was successfully fabricated.

Free Research Field

電気電子材料工学関連

Academic Significance and Societal Importance of the Research Achievements

本研究では，従来の単接合型太陽電池を超える性能が期待される多接合型太陽電池のトップセル発電層として有望なCu(In,Ga)Se2(CIGSe)系に着目し，(1)固液界面を介した結晶制御法の開発による高品質な禁制帯幅1.65 eVのCIGSe薄膜材料を創出する.また,(2)豊富な材料群で既に開発されている禁制帯幅1.1 eVのボトムセルとの自在な多接合化に向けて,ガラス基板上で作製したCIGSe太陽電池のCIGSe/Mo界面の密着性制御による素子剥離法を確立する.