Electronic excitations localized in KBr and KI crystals near vacancy defects of different sizes

Abstract

Abstract The luminescence and excitation spectra of electronic excitations localized near a single anion vacancy (e α ), a divacancy (e d ), and a vacancy quartet (e q ) are investigated. The shifts of spectral characteristics of these excitations with respect to those of the excitations in regular lattice sites (e r ) have regular behavior. It turned out that the charge of vacancy defects is the main perturbing factor for e α , e d , and e q creation and the dimension of vacancy defects is the main perturbing factor for the radiative decay e α , e d , and e q . The peculiarities of e α , e d , and e q relaxation are discussed in terms of strong and weak off‐centers for e r in KBr and KI, respectively.