Optical Absorption due to Intrinsic Defects in CdS Single Crystals

Abstract

Abstract Optical absorption spectra due to intrinsic defects in CdS were measured between 0.13 and 2.5 eV, at 80 °K. The results indicate that Cd interstitials (Cd i ) and Cd vacancies (Vcd) are the dominant electronically active defects, which act as double donors and double acceptors, respectively. A detailed discussion of the properties of the observed absorption bands, in particular their shape, polarization, and the effects of Cd and S heat treatment, leads to assignments to optical transitions at isolated Cd i and Vcd and at nearest‐neighbour donor‐acceptor associates between these intrinsic defects and impurity ions.