Spin-orbit coupling and crystal-field splitting in the electronic and   optical properties of nitride quantum dots with a wurtzite crystal structure
  We present an $sp^3$ tight-binding model for the calculation of the electronic and optical properties of wurtzite semiconductor quantum dots (QDs). The tight-binding model takes into account strain, piezoelectricity, spin-orbit coupling and crystal-field splitting. Excitonic absorption spectra are calculated using the configuration interaction scheme. We study the electronic and optical properties of InN/GaN QDs and their dependence on structural properties, crystal-field splitting, and spin-orbit coupling. 
S. Schulz, S. Schumacher, G. Czycholl