Controlling the defect density in CIGS films

The sensitivity of CIS-alloys to the deposition parameters and the ambience has been attributed to their Ga content and its deep defect density. This work investigates a chemical approach to maneuver CIGS defects. It develops a simple processing step to reconfigure CIGS defects, aiming at enhanced photovoltaic (PV) efficiency, simpler fabrication and minimum environmental hazard. Photocurrent spectra of CIGS films in an electrolytic medium monitor the effects of surface treatments and specific metal ions. The results provide interesting insights into the effects of stoichiometry and air-oxidation on the defect chemistry of the CIGS film. They could lead to substantial impact on the performance and manufacturing of inexpensively deposited CIGS films.