Modelling of Band Offsets in II-VI Heterostructures

We present a new tight binding view of band offsets in group II-VI based heterojunctions. The model considers the nonorthogonality of sp 3 set of orbitals of adjacent atoms and the interaction of bonding and antibonding states at high symmetry points in calculating the valence band energies at 0 K and 1 bar. The valence band offsets are then obtained from the difference between the valence band energies, screened by the optical dielectric constants, of bulk semiconductors at equilibrium across interfaces. Excellent agreement with experiment suggests that the bulk band structure properties play significant role in determining the band offsets for lattice matched heterojunctions.