Theoretical simulation of optoelectronic and structural properties of ASiN2 (A = Be, Mg, Ca, Sr) semiconductors

Abstract

Using first-principles calculations, we have explored the structural, electronic and optical properties of ternary chalcopyrites ASiN2 (A = Be, Mg, Ca, Sr). The calculations were performed with the modified Becke-Johnson (mBJ) exchange potential, shows that the ASiN2 (A = Be, Mg) compounds have a direct band gap while CaSiN2 and SrSiN2 have an indirect gap. We present the results of band structure and density of states, which predicts that the energy band gap of these compounds decreases when we migrate from Be to Sr. The electron charge density plots understood the interlayer and chemical bonding properties, which also revealed the materials' unique traits with regard to their optical properties. The dielectric function, absorption coefficient, refractive index, and optical conductivity have all shown significant changes. The calculated optical results show that these materials are promising semiconductors for photovoltaic applications.