Strain relaxation and band-gap tunability in ternary InxGa1-xN nanowires

The alloy formation enthalpy and band structure of InGaN nanowires were studied by a combined approach of the valence-force field model, Monte Carlo simulation, and density-functional theory (DFT). For both random and ground-state structures of the coherent InGaN alloy, the nanowire configuration was found to be more favorable for the strain relaxation than the bulk alloy. We proposed an analytical formula for computing the band gap of any InGaN nanowires based on the results from the screened exchange hybrid DFT calculations, which in turn reveals a better band-gap tunability in ternary InGaN nanowires than the bulk alloy.

U.S. Department of Energy DE-AC36-99GO10337 Chinese Academy of Sciences Work at NREL was supported by the U.S. Department of Energy under Contract No. DE-AC36-99GO10337. We thank G. Kresse for providing us the VASP 5.1 code. J.L. gratefully acknowledges financial support from the "One-Hundred Talents Plan" of the Chinese Academy of Sciences.