Band gap bowing and crossing of BxGa1−xN alloy investigated by hybrid functional method**Project supported by the Fundamental Research Funds for the Central Universities (No. 2010LKWL03), the Special Fund for Theoretical Physics (No. 11047130), and the National Natural Science Foundation of China (No. 11104345).

Abstract

The electronic properties of zinc-blende BxGa1–xN alloys are comparatively investigated by employing both the Perdewe-Burkee–Ernzerhof generalized-gradient approximation (PBE-GGA) and the Heyd-Scuseria-Ernzerhof screened hybrid functional methods (HSE06). HSE06 reproduced much closer ground-state properties to experiments. Large and composition-dependent bowing parameters bγ for the direct band gaps were obtained from both PBE and HSE06. The crossover composition where alloy switches from direct to indirect was predicted to occur at very similar x from PBE and HSE06. We can obtain direct gap BxGa1–xN with a gap value much larger than that of GaN by alloying x < 0.557 boron into GaN.