Hybrid functional study of band structures of GaAs_(1-x)N_x and GaSb_(1-x)N_x alloys

摘要

Band structures of GaAs_(1-x)N_x and GaSb_(1-x)N_x. alloys are studied in the framework of the density functional theory within the hybrid functional scheme (HSE06). We find that the scheme gives a clear improvement over the traditional (semi)local functionals in describing, in a qualitative agreement with experiments, the bowing of electron energy band gap in GaAs_(1-x)N_x alloys. In the case of GaSb_(1-x)N_x alloys, the hybrid functional used makes the study of band structures possible ab initio without any empirical parameter fitting. We explain the trends in the band gap reductions in the two materials that result mainly from the positions of the nitrogen-induced states with respect to the bottoms of the bulk conduction bands.