Chalcopyrite Thin-Film Materials and Solar Cells

The materials science and device physics of chalcopyrite-type thin-film materials and solar cell devices are reviewed. Chalcopyrite-type polycrystalline materials are very versatile multinary materials with excellent optical and electronic properties and a high degree of chemical flexibility, which are naturally suited for high-efficiency thin-film solar cells. Although small area record devices now exceed 20% photoconversion efficiency, the underlying reasons and conditions enabling such high efficiencies in specific devices are complex and require a thorough understanding of the material physics and device properties of the heterojunction solar cells. A wide variety of different deposition methods can be used to deposit chalcopyrite thin films suited for solar cells, with advantages and disadvantages regarding cost, scalability, and throughput. Recently, commercialization of chalcopyrite thin film has been scaled up to the GW range, proving the competitiveness of this technology with regard to crystalline silicon solar technology.