Optical and electronic properties of BxAl1−xP alloys: A first principles study

The electronic, optical and thermodynamic properties of boron alloying aluminum phosphide (BxAl1−xP) ternary mixed crystal are studied by the first-principle calculations within the framework of the density functional theory (DFT). Our calculated lattice constants and bulk moduli for AlP and BP are in good agreement with the available theoretical and experimental data. The lattice constants decrease while the bulk modulus increases with B concentration increasing. The calculated band structure for the concentrations x = 0.25, 0.50, and 0.75 are direct gap semiconductors. The density of states and optical constants such as complex dielectric function, extinction coefficient, refractive index and absorption coefficient are also calculated and analyzed in detail. Moreover, the thermodynamic stability of these alloys is investigated by the calculated T − x phase diagram.