ELECTRONIC AND OPTICAL PROPERTIES OF TiS_2 DETERMINED FROM MODIFIED BECKE-JOHNSON GGA POTENTIAL (mBJ-GGA) STUDY

摘要

In this study, we report the results of electronic structure and optical properties of TiS_2 calculations within the density functional theory (DFT) using the generalized gradient approximation (GGA) and an improved version of the modified Becke-Johnson (mBJ) exchange-correlation potential. The equilibrium lattice parameters and bulk modulus were found to be close to the experimentally reported results and a semi-conducting character of the material was revealed from the band structure calculation with an indirect band gap of 0.26 eV. Furthermore, DOS plots showed a prominent contribution of Ti-d, S-s and S-p. We have also calculated the dielectric function, refractive index and optical reflectivity and we have compared the obtained curves to those found experimentally by other authors.