DX like InCu and GaCu defects in chalcopyrite based solar cells

Red illumination of the reverse biased device ROB causes persistent increase of the capacitance of CIGS based solar cells. ROB effect can only be explained in terms of relaxing defects, undergoing shallow deep transition. According to theoretical calculations, IIICu defect is a probable candidate. We demonstrate here that ROB effect is present in all CIGS chalcopyrite compounds including wide band gap CuGaSe2 and CuInS2 and show that photovoltaic parameters of the devices depend on the charge state of the antisite defect. The role of the blue part of the illumination spectrum for establishing favorable charge distribution is demonstrated. The relation between the Fermi level position at interface and the antisite influence on the photovoltaic parameters is discusse