First principles study of wurtzite and zinc blende GaN: a comparison of the electronic and optical properties

The electronic and optical properties of zinc blende and wurtzite structure GaN are studied from DFT based first principle calculations. The (partial) density of states (DOS) is calculated and differences between the zinc blende and wurtzite GaN are compared. Results show that the DOS around the Fermi level for the wurtzite structure is much lower than that of the zinc blende structure and results in a wider band gap. The complex refractive indexes and the absorption coefficients are calculated under normal and high external pressure. Results show that wurtzite GaN is more suitable for blue light emission material.