Determination of Cu(In1−xGax)3Se5 defect phase in MBE grown Cu(In1−xGax)Se2 thin film by Rietveld analysis
Copyright policy )Determination of Cu(In1−xGax)3Se5 defect phase in MBE grown Cu(In1−xGax)Se2 thin film by Rietveld analysis
Abstract Quantitative phase analysis of Cu(In 1− x Ga x )Se 2 (CIGS) thin film grown over Mo coated soda lime glass substrates was studied by Rietveld refinement process using room temperature X-ray data at θ –2 θ mode. Films were found to contain both stoichiometric Cu(In 1− x Ga x )Se 2 and defect related Cu(In 1− x Ga x ) 3 Se 5 phases. Best fitting was obtained using crystal structure with space group I-42d for Cu(In 1− x Ga x )Se 2 and I-42m for Cu(In 1− x Ga x ) 3 Se 5 phase. The effects of Ga/III (=Ga/In+Ga= x ) ratio and Se flux during growth over the formation of Cu(In 1− x Ga x ) 3 Se 5 defect phase in CIGS was studied and the correlation between quantity of Cu(In 1− x Ga x ) 3 Se 5 phase and solar cell performance is discussed.