Variations of thioacetamide treatments on CIGS solar cells on stainless steel substrates - correlations to device performance

The details of design of experiment (DOE) studies involving thioacetamide treatment performed on Cu(In/sub 1-x/Ga/sub x/)Se/sub 2/ (CIGS) deposited on stainless steel are discussed. CIGS films were treated in an aqueous InCl/sub 3//thioacetamide (CH/sub 3/CSNH/sub 3/) bath varying time, temperature and salt as well as CH/sub 3/CSNH/sub 3/ concentration in order to determine the optimum conditions for surface sulfurization. Subsequent device completion employing a CBD CdS buffer was performed under nominally identical conditions. The resulting devices were compared on the basis of deposition conditions including untreated control specimens. Device efficiencies in this study ranged from 6 to 11% and did not show significant improvement over untreated controls. Procedures, results, and possible causes for disagreement with earlier studies are discussed.