Infrared Studies of Al Complexes in Zinc Sulphide

Abstract

Abstract Infrared absorption is studied in zinc sulphide doped with the following impurities: a) Al and Cu, b) Al and Ag, c) Al and Au. Al is introduced during crystal growth and Cu, Ag, and Au by saturation diffusion. The ZnS samples with two dopants have the zincblende structure with a low density of stacking faults. In the spectral range 360 to 650 cm −1 a number of absorption bands are observed that could be ascribed to the localized vibrational modes of unassociated Al and Al in complexes with Cu, Ag or Au. On the basis of symmetry considerations the following defect models are suggested: Al Zn , Al Zn –Cu Zn , Al Zn –Au Zn and Al Zn –Ag S or Al Zn –Ag i (where i denotes interstitial location). The results obtained with ZnS are compared with published data for CdTe and ZnSe.