Compositional and optoelectronic properties of CIS and CIGS thin films formed by electrodeposition

CuInSe₂ (CIS) and Cu(In,Ga)Se₂ (CIGS) thin films were prepared by electrodeposition and processing. The influence of film deposition parameters such as bath composition, pH, deposition potential and material purity on film properties was studied. The structural, morphological, compositional and opto-electronic properties of electrodeposited and selenized CIS and CIGS thin films were characterized using various techniques. As-deposited as well as selenized films exhibited a compact or a granular morphology depending on the composition. The film stoichiometry was improved after selenization at 550°C in a tubular furnace. The films are formed with a mixed phase composition of CuInSe₂ and CuIn₂Se_3.5 ternary phases.