2016年 第77回応用物理学会秋季学術講演会

講演情報

シンポジウム(口頭講演)

シンポジウム » 多元系化合物の機能性評価技術の新展開 ―多元系デバイス開発への知見提供―

[13p-B9-1~11] 多元系化合物の機能性評価技術の新展開 ―多元系デバイス開発への知見提供―

2016年9月13日(火) 13:30 〜 18:00 B9 (展示ホール内)

加藤 拓也(ソーラーフロンティア)、坪井 望(新潟大)

14:30 〜 14:45

[13p-B9-3] Effect of Post-deposition Se-annealing on the defect distribution in CuGaSe2 Thin-films and Solar-cells

Muhammad Monirul Islam1、Akira Uedono1、Takeaki Sakurai1、Christoph Hugenschmidt2、Werner Egger3、Roland Scheer4、Ayham Dalla4、Reinhard Krause-Rehberg4、Katsuhiro Akimoto1 (1.Tsukuba Univ.、2.Tech. Univ. Munchen、3.Univ. Bundeswehr Munchen、4.Martin Luther Univ. Halle)

キーワード:CuGaSe2, Se-annealing, photovoltaic

Chalcopyrite Cu(In,Ga)Se2 (CIGS) being a pseudo-binary alloy of ternary CuInSe2 and CuGaSe2 is one of the most promising materials to realize high-efficiency thin-film solar cell. Band-gap of the CuGaSe2 is 1.68 eV which is close to the ideal band-gap (1.4 eV under AM 1.5 sunlight) of the absorber-layer to achieve the highest possible efficiency. Moreover, larger band-gap makes the CuGaSe2 suitable for the top-cell in the tandem structure together with CuInSe2 as the bottom-cell. Nevertheless, so far, CuGaSe2 solar cells with a CdS buffer have achieved efficiency of around 11 % for the thin film. Therefore, to achieve the optimized material quality of the CuGaSe2 material which is compatible for highest possible efficiency, an extensive study of this material with various compositions is indispensable. In this paper, we have changed the post-deposition Se-annealing time to study the effect of Se-annealing on the properties of CuGaSe2. Se-annealing was found to affect both the surface and also bulk of the film by controlling the defect-distribution along the depth of the film. Mechanism of the defect distribution has been investigated. Performance of the fabricated solar cells has been studied in correlation to the Se-annealing time.