ELECTRONIC AND OPTICAL PROPERTIES OF STRAINED WURTZITE GaN

Band structures of wurtzite GaN (\alpha-GaN) under strains in the region -5%—5% are calculated in a tight-binding framework. The empirical scaling rule has been used for considering the effects of hydroatatic strains. The scaling indexes are determined by fitting the deformation-potential constants with other theoretical values. The band gap at \Gamma point increases with the absolute value of strains. GaN turns to be of indirect band gap when strains reach 5 %. The density of states and the imaginary part of dialectic function (\varepsilon₂(\omega)) are studied. Both the shape and energy position of the highest peak in the \varepsilon₂(\omega) spectrum successively change with the strains. The real part of dielectric/unction, refractive index and the effects of the strains on them are also shown.