ELECTRONIC AND OPTICAL PROPERTIES OF WURTZITE GaN:——A THEORETICAL APPROACH

The band structures of wurtzite GaN(\alpha-GaN) are studied using the nearest and second-nearest neighbour semi-empirical tight-hinding method in sp³ s^* model. The calculated direct fundamental gap of \alpha-GaN is 3.45 eV, which is in good agreement with the experimental data. The density of states and the imaginary pert of dielectric function (\varepsilon₂ (\omega)) are evaluated to he in the regions - 10.0 - 12 eV and (1.0 - 10.0 eV, respectively. There are mainly three peaks at 6,4, 7,5, 8.4 eV, dominating the (\varepsilon₂ (\omega)) spectrum. The two components of the (\varepsilon₂ (\omega)) (i. e. \varepsilon_2xy(\omega) and \varepsilon_2z(\omega) ) are also calculated; and the real prat of dielectric function, reflectivity, absorption coefficient, and refractive index are all studied.