Theoretical study of the Be_xZn_1-xO alloys and Mg-doped Be_xZn_1-xO alloys

The geometry structure of 16-atom supercell of Be_nZn_8-nO₈ and Mg₁Be_nZn_7-nO₈ was optimized by adopting the method of ultrasoft pseudopotential technology of total energy plane wave based upon the density functional theory (DFT). Cell parameters and total energy were calculated. Band structures and partial density of states of BeO, lattice parameters and stability of Be_xZn_1-xO and Mg-doped Be_xZn_1-xO alloys, and energy bowing parameters of Be_xZn_1-xO are calculated and analyzed. The results indicate that the structure of Be_xZn_1-xO alloys are very stable, calculated lattice parameters are in good agreement with experimental results, and also close to Vegard's law, the calculated bandgap bowing parameter is as large as 5.6eV. It is also revealed that the problem of lattice mismatch can be solved, the band off-set can be increased, and the stability of Be_xZn_1-xO alloys can be increased by doping a little amount of Mg atoms.