Admittance spectroscopic measurements were performed on thin-film and monocrystalline heterojunctions. It was found that the emission rates of defects, for various near-stoichiometric compositions, obeyed a Meyer-Neldel rule; thus revealing an increased attempt-to-escape frequency ratio with increasing defect depth. The defects in very (In,Ga)-rich material exhibited lower attempt-to-escape frequency ratios, and obeyed a different Meyer-Neldel relationship. Repetitive annealing in air, of a CuInSe2 heterojunction, revealed a shift in the depth and capture cross-section of an observed defect.

R.Herberholz, T.Walter, C.Müller, T.Friedlmeier, H.W.Schock, M.Saad, M.C.Lux-Steiner, V.Alberts: Applied Physics Letters, 1996, 69[19], 2888-90