Investigation of Structural, Electronic, and Optical Properties of Strontium Chalcogenides

In this study, the structural, electronic, and optical properties of strontium chalcogenides are investigated by the pseudopotential method in the framework of density functional theory and quantum espresso code. The calculations were performed with the LDA, GGA, and HSE approximations. The calculated structural parameters are in good agreement with available experimental and theoretical data. The results of the band structure show that these compounds in B1 phase are semiconductors with an indirect band gap. The band gap calculated for compounds in B1 phase in the LDA and GGA approximations is consistent with the theoretical data of others. Also, the band gap in HSE approximation for SrS, SrSe, and SrTe compounds were calculated 4.30, 3.86, and 2.96 eV, respectively, which is in agreement with the experimental data. The dielectric constant for SrS, SrSe, and SrTe compounds was calculated as 4.73, 5.02, and 5.86 in GGA and 5.27, 5.48, and 6.50 in the LDA approximation, respectively and these results are also consistent with available experimental and theoretical data.