Band Bowing in BeSexTe1−x

BeTe and BeSe are wide‐band gap and highly mismatched semiconductors (HMS). The band bowing of BeSexTe1−x originates in the mismatch of size and orbital energies between Te and Se and is under‐predicted by virtual crystal approximation. The recent band anti‐crossing (BAC) model explains the band bowing in highly mismatched semiconductors. We extend the BAC model to empirical tight‐binding (ETB) theory. We use the sp3s* model and calculate the band bowing of the on‐site (self‐) energies for an arbitrary concentration x. The results are applied to calculation of electronic and optical properties of BeSe0.41Te0.59 lattice matched to Si in a superlattice configuration.