Compositional dependence of refractive index and oscillator parameters in TlGaS2xSe2(1−x) layered mixed crystals (0 ≤ x ≤ 1)

► Spectral dependence of refractive index for TlGaS2xSe2(1−x) crystals were obtained. ► The dispersion of refractive index is discussed using Wemple-DiDomenico model. ► Compositional dependencies of oscillator and dispersion energies were revealed. ► It was established that these parameters decrease with increasing the sulfur content.