Ab initio Insight of the Electronic, Structural, Mechanical and Optical Properties of X 3 P 2 (X= Mg, Ca) from GGA and Hybrid Functional (HSE06)

Abstract

In this paper, the structural, mechanical and optoelectronic properties of X3P2 (X= Mg, Ca) have been investigated by using the first-principles calculation. The obtained results from the structural and mechanical properties reveal that our X3P2 compounds are thermodynamically and mechanically stable. Moreover, the elastic constants and bulk modulus result imply that Mg3P2 is ductile and Ca3P2 is brittle. The calculated band structure reveals that our two compounds have a direct bandgap (Γ -Γ) of 0.523 eV and 0.446 eV for Mg3P2 and Ca3P2, respectively, from GGA. However, on using HSE06 hybrid functional the bandgap has been enhanced to 1.282 eV for Mg3P2 and 1.092 eV for Ca3P2. Both compounds exhibit a high optical absorption in the visible region (≥ 105cm- 1), making them potential candidate for photovoltaic applications.