摘要： Band structures of wurtzite GaN (α-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 Γ 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 (ε₂(ω)) are studied. Both the shape and energy position of the highest peak in the ε₂(ω) 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.

Abstract: 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 ($\varepsilon$₂($\omega$)) are studied. Both the shape and energy position of the highest peak in the $\varepsilon$₂($\omega$) 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.

中图分类号:  (Semiconductor compounds)

• 71.20.Nr

71.15.Ap (Basis sets (LCAO, plane-wave, APW, etc.) and related methodology (scattering methods, ASA, linearized methods, etc.)) 71.45.Gm (Exchange, correlation, dielectric and magnetic response functions, plasmons) 78.20.Ci (Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity))