Post-deposition Metal Halide Treatment of CuGaSe2 for Photovoltaic Application

Deewakar Poudel1, Benjamin Belfore1, Adam Masters1, Elizabeth Palmiotti2, Angus Rockett2, Sylvain Marsillac1 1Virginia Institute of Photovoltaics, Old Dominion University, Norfolk, VA, United States /2Dept. of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, CO, United States

Copper gallium diselenide (CGS) semiconductor thin films were deposited by three-stage thermal co-evaporation process. Post-deposition treatments and recrystallization were performed at various AgBr doses of 40 mg, 60 mg, and 80 mg after the 2nd stage. The changes in surface morphology were confirmed by SEM. The electrical properties were also modified, as the resistivity of the film decreases with increasing doses. The device performance after the treatment did not change as expected, as the overall device performance only slightly increases in the case of 60 mg of AgBr. Substantial changes in the fabrication process will therefore be required for better device results.