First-principle studies of optical properties of Be_xZn_{1- x}O ternary mixed crystal

The optical properties of beryllium doped zinc oxide (Be_xZn_1-xO) ternary mixed crystal are studied by the first-principles calculations within the framework of the density functional theory (DFT). It turned out that as the energy increases the real parεt ε₁of the dielectric function of Be_xZn_1-xO first reached a maximum peak and then gradually attenuated, the static dielectric constant of Be_xZn_1-xO decreases as the Be component increases, the imaginary part ε₂of the dielectric function represents light absorption, as the Be component increases, the three main peaks are constantly moving towards the high-energy tail. The refractive index and reflectivity of Be_xZn_1-xO ternary mixed crystal are decreases with increasing Be concentrations, the blue shift of absorption spectrum of the system becomes more significant. Obtained smooth varying of the optical properties is related to the gradual decreasing of the lattice parameter of Be_xZn_1-xO and increasing of the bandgap.