Main effects of oxygen centers in A-=SUP=-II-=/SUP=-B-=SUP=-VI-=/SUP=- optics

Abstract

On the basis of the studies carried out, it is shown in the work that the influence of oxygen on the optical properties of AIIBVI crystals is determined by three main effects. This is the formation of a system of bound excitons accompanying the presence of high oxygen concentrations at stacking faults --- a long-wavelength shift by hundreds of meV of the absorption edge, and the third effect is determined by the emergence of broadband "self-activated" SA luminescence in the near-edge region of the spectrum. This work introduces the concept of a non-uniform distribution of isoelectronic oxygen centers in the bulk of crystals, both due to their predominant segregation at stacking faults and in layer of stacking faults. To analyze the optical data, we used the capabilities of the method for constructing band models, which collects extensive and multilateral information about specific samples. A refined models of the CdS(O) and ZnSeSe(O) multizone with stacking faults is presented. The paper describes the conditions and the possibility of joint and separate observation of these features in the spectra of different crystals AIIBVI and using them to create lasers. Keywords: band model, bond excitons, additional absorption edge AAE, point defects, stacking faults, band anticrossing theory (BAC), laser effect.