Thermodynamic and experimental study of chemical bath deposition of Zn(S,O,OH) buffer layers in basic aqueous ammonia solutions. Cell results with electrodeposited CuIn(S,Se)2 absorbers

This paper presents a thermodynamic study of Chemical Bath Deposition (CBD) of zinc sulphide based films in aqueous ammonia solutions. The aim is a better understanding of ammonia and temperature effects on the deposition conditions and films composition. The formation of solid phases has been predicted by means of the precipitation conditions of ZnO, Zn(OH)2 and ZnS as a function of temperature between 298 and 333 K. Films have been deposited according to calculated diagrams and preliminary results on solar cells based on electrodeposited CuIn(S,Se)2 layers have been demonstrated. Composition and thickness of the films have been extracted to link the theoretical study with experiments.