Electronic and Optical Properties of the TlIn3S5 Crystals: Ab Initio Calculation and Experiment

The electronic band structure, origin of energy states, partial densities of states projected onto atoms, and spectral dependences of optical functions at different polarizations of incident light for the TlIn3S5 crystals have been studied using ab initio calculations. Good applicability of the single effective oscillator model to the TlIn3S5 crystals is demonstrated. The TlIn3S5 crystals have been synthesized at room temperature and their luminescence spectrum and dependence of the photoluminescence intensity on the exciting radiation power have been experimentally studied. The nonlinear refractive indices and the first- and third-order nonlinear susceptibilities have been calculated, which indicate the prospects of integration of the compound into various nonlinear optical systems.