Homogeneous CuGaSe2 growth by the CuPRO process with In-Situ AgBr treatment

Homogeneous CuGaSe2 thin film growth is limited by slow kinetics of formation. A modified growth process was previously developed to address this issue but requires two separate long, high temperature anneals. Here, we demonstrate that a short AgBr treatment can replace this modified growth process. The AgBr works as a transport agent to catalyze CuGaSe2 formation and atomic mobility. This treatment results in large grains with homogeneous composition through the bulk. Solar cells made with this material show better performance.