Energy band gap of β-GaN and its variation with pressure

A semi-empirical calculation has been carried out to find out the energy band gap of Gallium Nitride in Zinc Blende structure. The normal or zero pressure lattice constant has then been used as variable parameter, and the band gap and the deformation potential has been calculated for ten values of the parameter below and above the normal lattice constant. The lattice parameter variation corresponds to pressure variation of about +/-300 Kbar. The band gap is not found to vary linearly, the E-g --> a curve showing concavity upwards, thereby eliminating the possibility of a transition to metallic phase. The results are compared with available data from other reported works.