Effects of strain on the [formula omitted] electronic structure and related properties of w-GaN

Abstract

We consider effects of strain on the k→⋅π→ electronic structure by modifying non-strain k→⋅π→ theory in the presence of uniaxial/biaxial stress and hydrostatic pressure. Here π→ is the relativistic momentum operator and k→ is the wave vector of an electron. The theory is applied to w-GaN. Starting from a non-relativistic electronic Hamiltonian, we show the changes brought about by strain in the position operator, momentum operator and the periodic potential. We extend it to the relativistic Hamiltonian, and then to the k→⋅π→ theory. We modify the k→⋅π→ electronic structure of non-strained w-GaN, previously developed by one of the authors, by incorporating the strain effects on the Luttinger-Kohn parameters. Effect of strain is considered on the Γ-point conduction and valence band energies. Inter-band transition energies are also calculated. We study strained valence band dispersions. Our results agree with previous calculations wherever such calculations exist. Discrepancies, if any, are addressed. We also consider the effect of strain on the effective mass and g-factors of both electrons and holes, in view of their importance in transport and other properties and spintronics. Effective mass results compare well other available calculations. Results for the g-factors are new and show interesting trends.