Miniband structures and effective masses of n-type -doping superlattices in GaN
Self-consistent electronic structure calculations of n-type -doping superlattices (SLs) in GaN are performed using effective-mass theory and local density functional theory. The electron bulk mass of cubic GaN is obtained from ab initio full potential linear augmented plane wave (FLAPW) band-structure calculations. For the SLs, self-consistent potentials, subband levels, miniband dispersions and Fermi-level positions are calculated, assuming sheet donor concentrations up to and periods between 50 A and 400 A which cover the whole range between an isolated-well and SL regime. The miniband effective masses exhibit strong dependence on the SL wavevector. The confinement effects in GaN n-type -doping SLs are strong enough to be seen experimentally in transport and optical properties. A comparison of the results obtained for GaN with -doped layers in other III-V compounds, such as GaAs, is made.