Theoretical studies on the structural, electronic and optical properties of BeZnO alloys

The structural, electronic and optical properties of Be_xZn_1−xO alloys were studied using the density functional theory and Hubbard-U method. U_o;p = 10.2 eV for O 2p and U_Zn;d = 1.4 eV for Zn 3d were adopted as the Hubbard U values. For Be_xZn_1−xO alloys, the lattice constants a and c decrease linearly as Be concentration increases, the bandgap increases with a large bowing parameter of 6.95 eV, the formation enthalpies have the maximum value with Be concentration at 0.625, corresponding to the possible Be concentration to form phase separation. These calculations comply well with the experimental and other theoretical results. Furthermore, optical properties, such as dielectric function ∈(ω), reflectivity R(ω), absorption coefficient α(ω), were calculated and discussed for Be_xZn_1−xO alloys with the incident photon energy ranging from 0 eV to 30 eV.