Metastable defect in CuInSe2 probed by modulated photo current experiments above 390 K
Abstract
Modulated photocurrent experiments have been widely used to study defects in semiconductors. Previous studies have found a number of defects in CuInSe2, which is used as an absorber in solar cells. We apply a method of analysis, which has previously not been used for Cu(In,Ga)Se2 semiconductors and which allows the determination of defect concentrations in addition to defect energies. We found that at least one of the previously discovered defects shows a metastable behaviour, increasing in concentration, and can be related to the efficiency loss in corresponding solar cells.