Electronic band parameters for zinc-blende Al_1−xGa_xN

Band-structure calculations are performed for cubic Al_1−xGa_xN using the empirical pseudopotential method. The band gaps at Γ, X and L points and the electron effective masses of Γ and X valleys are calculated as a function of the gallium fraction x. It is found that there is no significant change in these electronic band parameters on taking into account the alloy disorder. On the basis of a model solid theory, we have calculated the band discontinuities for heterointerfaces between strained Al_{1 −x}Ga_xN and relaxed Al_1−yGa_yN. The latter calculations are extended to the whole range of compositions x and y. The information derived from this investigation will be useful in the design of lattice-mismatched heterostructures in blue-light optoelectronics applications.