Fabrication of Cu2SnS3 thin film solar cells by sulphurization of sequentially sputtered Sn/CuSn metallic stacked precursors. (1st January 2019)

• Record Type: Journal Article
• Authors: Hossain, Ejarder Sabbir; Chelvanathan, Puvaneswaran; Shahahmadi, Seyed Ahmad; Bais, Badariah; Akhtaruzzaman, Md.; Tiong, Sieh Kiong; Sopian, Kamaruzzaman; Amin, Nowshad
• Is Part Of: Solar energy. Volume 177(2019)
• Page Start: 262
• Page End: 273
• Publication Date: 2019-01-01
• Subjects: Cu2SnS3 solar cells -- Photovoltaic technologies -- Thin film deposition -- SnS secondary phase; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2018.10.081
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: Elemental-alloy Sn/CuSn precursors were sputtered with different Sn content. Cu/Sn ratio of metallic precursor dictates characteristics of CTS film and device. Metallic precursor with Cu/Sn = 1.09 produced optimum CTS film properties. Best efficiency of 0.71% was obtained from optimized CTS device. Abstract: In this present work, we report a novel fabrication technique of ternary Cu2 SnS3 (CTS) thin films by sulphurization of sequentially sputtered Sn/CuSn (elemental/alloy) stacked metallic precursors. The focal aim of our investigation is on the impact of metallic precursors' Cu/Sn ratio on the overall material properties of CTS films, which in turn, influence the photovoltaic device performance. All CTSs exhibited polycrystalline films with a mixture monoclinic CTS and orthorhombic SnS compound, p-type conductivity, and optical band gap in the range of 0.84–0.90 eV. Metallic precursor with Cu/Sn ratio of 1.09 produced optimum CTS film with post-sulphurization Cu/Sn ratio of 1.98 and highest conversion efficiency of 0.71%, respectively, despite exhibiting pronounced formation of SnS secondary phase. The correlation between XRD, Raman, and SEM-EDX outcomes revealed that CTS films from metallic precursors with Cu/Sn ratio higher than 1.09 undergo severe microstructural degradation due to Sn-loss through decomposition of volatile SnS phase and consequently, resulted in poorer absorber layer quality and lower device performance. Finally, several efficiency impeding factors are discussed and practical propostions to overcome them are presented.