Electronic properties of GaPxAs1-x ternary alloy: A first-principles study

The electronic properties of GaPxAs1-x ternary semiconductor alloy including effective band structures, density of states and effective masses were studied from first principles using supercell (SC) approach. The modified Becke-Johnson (MBJ) exchange potential together with correlation part of both the local density approximation (LDA) and M06 of Minnesota functionals were used to obtain accurate band structure profile. The effective band structures of alloys were calculated using spectral weight approach and composition dependence of the fundamental gap energy and electron effective masses were estimated from it. The results of the supercell calculations for energy gap and bowing parameters for both direct and indirect gaps are in good agreement with the experiments. The results also show that crossover point of (Γ-Γ) direct and (Γ-x) indirect gap energies occurs at x = 0.46, which is in excellent agreement with the experiments. Furthermore, our results show that the combination of MBJ exchange and M06 correlation potential can be used to estimate accurate band structure profile for GaP, GaAs and their alloys.