Solution-processed CuIn(S,Se)2 absorber layers for application in thin film solar cells

A pure solution-based approach is proposed for the fabrication of high quality CuIn(S,Se)2 (CIS) thin films. This is an alternative procedure to the hydrazine-based route and involves the dissolution of metal chalcogenides in a safer solvent combination. The solvent mixture used in this work has the same advantages as hydrazine, such as good solubility of metal chalcogenides and clean decomposition, which is a prerequisite for high quality absorber layers. The solvents that are used are also much less toxic compared to hydrazine and can potentially result in a more feasibly industrially scalable deposition technology for CIS and the related alloys including Cu(In,Ga)(S,Se)2 (CIGS). The characterization of the obtained thin film material verifies the presence of the CIS chalcopyrite phase with good crystal growth.