Electronic and Optical Properties of the TlInS2 Crystal: Theoretical and Experimental Studies

Investigations on the electronic and optical properties of a TlInS2 layered crystal in the framework of density functional theory were carried out. The electronic band spectrum and the partial density of states were calculated including the dispersion correction. The impact of +U correction term on the bandgap values was analyzed as well. Based on the band structure calculations, optical characterisation was made for the first time for TlInS2, such as the real and imaginary parts of the dielectric function, the refractive index, and the absorption coefficient. Theoretical results of dielectric function and refractive index were compared to the measurement results.