Electronic structure and radiative lifetimes of ideal Zn1−xBexSe alloys

The electronic band structures of Zn1−xBexSe alloys are computed employing the virtual crystal approximation and empirical pseudopotentials. Pseudopotential form factors for ZnSe are fitted to experimentally determined critical point energies, and those for BeSe to generalized density functional theory computed band structures. The direct–indirect crossover alloy composition ratio is predicted to be x=0.43. At x=0.45, when Zn1−xBexSe is lattice matched to Si, radiative lifetimes of ideal structures are computed to be 4–6μs over the 250–400K temperature range.