Origin of Band Tail and Deep Donor States in Cu2ZnSnS4 Solar Cells and Their Sup

By comparing optical spectral results of both.Sn-rich and Sn-poor Cu2ZnSnS4 (CZTS) with the previously.calculated defect levels, we confirm that the band-tail states in.CZTS originate from the high concentration of 2CuZn + SnZn.defect clusters, whereas the deep-donor states originate from.the high c