Thin Film Deposition Methods for CuInSe 2 Solar Cells

Abstract

CuInSe2 and its alloys with Ga and/or S are among the most promising absorber materials for thin film solar cells. CuInSe2-based solar cells have shown long-term stability and the highest conversion efficiencies of all thin film solar cells, above 19%. Solar cells based on these materials are also very stable, thus allowing long operational lifetimes. The preparation of a thin film solar cell is a multistage process where every step affects the resulting cell performance and the production cost. CuInSe2 and other Cu chalcopyrites can be prepared by a variety of methods, ranging from physical vapor deposition methods such as evaporation and sputtering to low-temperature liquid phase methods such as electrodeposition. The present review discusses first the concept and operation principle of thin film solar cells, as well as the most important thin film solar cell materials. Next, the properties of CuInSe2 and related compounds, as well as features of solar cells made thereof are reviewed. The last part of the text deals with deposition methods used for the preparation of CuInSe2 and Cu(In,Ga)Se2 thin film absorbers and solar cells. Although the emphasis here is on absorber preparation methods, buffer and conducting oxide preparation are discussed as well.