Strain effects on the interface properties of nitride semiconductors

An ab initio study of nitride-based heteroepitaxial interfaces that uses norm-conserving pseudopotentials and explicitly treats the strain due to lattice mismatch is presented. Strain effects on the band offsets range from 20% to 40%. The AIN/GaN/InN interfaces (with AIN in-plane lattice constant) are all of type I, while the Al0.5Ga0.5N/AIN zinc-blende (001) interface is of type II. Further, the bulk polarizations in wurtzite ALN and GaN are -1.2 and -0.45 mu C/cm(2), respectively, and the interface contribution to the polarization in the GaN/AIN wurtzite multiquantum-well is small.