Studying the Recrystallization of Cu(InGa)Se2 Semiconductor Thin Films by Silver Bromide In-situ Treatment

Cu(In,Ga)Se2 samples were fabricated using a 3-stage thermal co-evaporation process on molybdenum back contact at low temperature. The process of recrystallization was carried out in between the 2nd and 3rd stages by flashing 25 mg of AgBr for 2 minutes. A change in morphological structure was observed as small grains transformed into large grains, as confirmed by XRD and SEM measurements. The decrease of the Ga gradient, seen in the SIMS depth profile, suggests Ga interdiffusion due to AgBr treatment. Overall, the AgBr treatment contributes to a general improvement in device performance as compared to the as-deposited devices.