Structural, mechanical, electronic and optical properties of BBi, BP and their ternary alloys BBi1-xPx

Abstract

The ground state properties of BBi, BP and their ternary alloys BBi1-xPx are reported using first-principles calculations based on density functional theory (DFT). The modified Becke-Johnson (mBJ) potential together with the generalized gradient approximation (GGA) for the correlation potential has been used here as it is a superior method for estimating band inversion strength and band order. The zincblende phase is found to be more stable than the other phases for all studied materials. The calculated lattice constants exhibit a small deviation from the linear Vegard's law with a downward bowing value of 0.11 angstrom. The calculated ground state parameters for the studied binary compounds agree with available theoretical and experimental results. The bandgap value of the studied materials calculated with the mBJ potential is considerably enhanced with respect to values from the GGA functional. Optical properties have been calculated and analysed with photon incident energy up to 21.0 eV. The spin-orbit interaction (SOI) has also been considered for structural and electronic calculations and the results are compared with those of non-SOI calculations. The real and imaginary parts of the dielectric function have also been calculated and discussed.