Theoretical study of structural, electronic, elastic and optical properties of SrS compound under pressure

Abstract

In this report, we theoretically studied the structural, elastic, electronic and optical properties of the binary compound SrS , using the CASTEP code, which is based on DFT, among many approximations to calculate the exchange and correlation energy, using the GGA-PBE approximation (GGA). Our results show that this compound crystallize in the NaCl -B1- structure at ambient conditions with indirect band gap about 2.521eV . Under hydrostatic pressure, the compound undergo a structural transition from the B1 phase to the CsCl -B2- structural phase for a pressure at 17.5GPa , Which is close to the theoretical value of 18GPa.The electronic and optical properties showed that this material is a semiconductor with a wide band gap with a very useful materials for high performance optoelectronic devices and laser diodes operating in the blue or ultraviolet spectral region. So the absorption spectrum indicates that this compound have a significant absorption in the ultraviolet range.In the -B2- phase and under the effect of pressure, the SrS compound change its electronic nature to become metallic at 69.1GPa. In general, our results were discussed and compared with the reference list and found to be in good agreement