Photoluminescence properties of thallium-containing GeSe$_{2}$ and GeSe$_{3}$ vitreous semiconductors

The photoluminescence properties of thallium-containing vitreous semiconductor systems with stoichiometric and nonstoichiometric compositions (GeSe$_{2}$)$_{1-x}$Tl$_{x}$ and (GeSe$_{3}$)$_{1-x}$Tl$_{x}$ (0 $\le x\le$ 0.1) are studied at a temperature of $T$ = 77 K. Intrinsic defects with negative correlation energy are responsible for the Gaussian shape of the photoluminescence spectra. It is established that an increase in $x$ in the systems does not affect the shape of the spectrum, does not generate new emission bands, shifts the photoluminescence spectra to the region of low energies, reduces the intensity of radiation, and increases its half-width. Kinetics of the fatigue of photoluminescence is different for both systems and is characterized by one curve irrespective of Tl content in the systems.