Frenkel excitons and the energy bands structure in crystals PbGa2S4

Abstract

On the basis of lead tiogalat (PbGa2S4) was created the active elements for lasers which allow to control the generation spectroscopic properties of lasers and parameters of the laser radiation. In these crystals were found Frenkel excitons with large oscillator strength (292meV) at room temperature. At a temperature of 10 K was observed the Wannier-Mott exciton. The contours of the exciton reflection spectra of Frenkel and Wannier-Mott excitons, for PbGa2S4 crystals, was calculated on the basis of dispersion relations.