Chapter 6: New Chalcogenide Materials for Thin Film Solar Cells

This chapter describes the search for new inorganic materials for thin film photovoltaic cells. It begins with the quest to bring down the cost of power generation by the move from crystalline silicon to thin film materials such as cadmium telluride (CdTe), copper indium selenide (CIS) and copper indium gallium diselenide (CIGS). The reliance of these materials on scarce and expensive elements, and the search for alternative sustainable materials, is then discussed. However, thoroughly investigating a new material is a protracted process and methods for surveying new compounds using high throughput or combinatorial techniques are presented. These reduce process time by growing a wide range of material compositions in parallel in a single specimen. Methods for thin film growth and analysis are discussed, as are the materials, Cu₂ZnSn(S,Se)₄ (CZTS), and the sulfosalt systems Cu–Sb–(S,Se), Cu–Bi–S and Sn–Sb–S.