Strain effects in group-III nitrides: Deformation potentials for AlN, GaN, and InN

A systematic density functional theory study of strain effects on the electronic band structure of the group-III nitrides (AlN, GaN, and InN) is presented. To overcome the deficiencies of the local-density and generalized gradient approximations the Heyd–Scuseria–Ernzerhof (HSE) hybrid functional is used. Cross checks for GaN demonstrate good agreement between HSE and exact-exchange based G0W0 calculations. We observe a pronounced nonlinear dependence of band-energy differences on strain. For realistic strain conditions in the linear regime around the experimental equilibrium volume a consistent and complete set of deformation potentials is derived.