Ab-initio Calculation of Optical Properties of the compound SnBi2Te4

In this research, optical properties such as dielectric function; Refractive index; Absorption coefficient
 and electron energy loss spectrum of SnBi2Te4 topological insulator have been calculated by using of Full potential linear augmented plane waves (FP-LAPW) within the framework of density functional theory (DFT) implemented in Wien2k code. PBE and LDA approximations have been used to calculate the exchange-correlation potential. The optical gap and the static refractive index have been obtained about 0.35 eV and 6.2. The absorption coefficient has two main peaks in 2.46eV and 7.36 eV that the second maximum is in the range of UV range and predicts that this material can be used in the field of UV-related devices such as sensors and detectors. The results are consistent with other available data.