Electronic and Optical Properties of (GaN)_n/(AlN)_n(001) Superlattices

The band structure of the short period zinc-blende (GaN)_n/(AlN)_n(001) superlattices has been calculated by means of semi-empirical tight-binding sp³s^* method. The superlattices energy gap dependence on layer number n is given out. On the basis of the calculated eigenfunctions and eigenvalues of the superlattices (SL), the imaginary parts of the dielectric function ε₂(ω) of (GaN)_n/(AlN)_n(001) superlattices were obtained. In order to compare with the optical properties of bulk zinc-blende GaN and AlN, we also calculated ε₂(ω) of the two compounds. It is shown that there are some discernible effects due to confinement and superlattice periodicity.