Theoretical Study of Optoelectronic Properties for Gallium nitride Under High pressure

The effect of the hydrostatic pressure and temperature on the direct energy gap in wurtzite and zinc-blende GaN semiconductor has been studied using different EOSs (Birch-Murnaghan, Bardeen, Libby and Libby, and Born-Mie). The variation of the energy gaps with pressure up to 12 GPa and with temperature up to 300 K has been done. The calculated fundamental energy gap at different pressures show a good agreement in comparison with the available experimental and theoretical data of literature. The effect of pressure on the refractive index of zinc-blende GaN has been studied. The refractive index decreases linearly with increasing pressure showing a negative pressure coefficient.