Electronic band structures and effective-mass parameters of wurtzite GaN and InN

The electronic band structures of wurtzite GaN and InN are calculated by the empirical pseudopotential method (EPM) with the form factors adjusted to reproduce band features which agree with recent experimental data and accurate first-principles calculations. The electron and hole effective masses at the Γ point are obtained using a parabolic line fit. Further, using the effective-mass Hamiltonian and the cubic approximation for wurtzite semiconductors, band edge dispersion at the Γ point obtained using the k.p method is fitted to that calculated using the EPM by adjusting the effective-mass parameters. Thus, we derived important band structure parameters such as the Luttinger-like parameters for GaN and InN which will be useful for material design in wide-gap nitride-based semiconductor lasers employing InGaN. The results also showed that the cubic approximation is fairly successful in the analysis of valence band structures for wurtzite nitrides.