Structural, electrical and optical properties of InxGa1-xN nanowires photocathode

[Display omitted] •The effects of H atom passivation and nanowire diameter on InN nanowires were analyzed.•Increasing the In composition will reduce the stability of the InxGa1-xN nanowires.•Increase of In composition shortens the bandgap of InxGa1-xN nanowires and makes the intrinsic absorption threshold response shifts to the lower energy region.•InxGa1-xN nanowires have excellent “light trapping” performance compared to bulk materials. First-principles calculations based on density functional theory are utilized to investigate the electronic and optical properties of composition-tunable InxGa1-xN bulks and nanowires, where four different compositions (x = 0, 0.33, 0.67, 1) were considered. In the established nanowire models, the electronic properties of bare InN nanowires and passivated InN nanowires with diameters of 3.732 Å, 6.378 Å, 9.567 Å were compared. The results show that increasing the In composition could reduce the stability of the InxGa1-xN nanowires, while increasing the nanowire diameter helps to improve the stability. In addition, the band gap of InxGa1-xN nanowires narrows with the increase of In composition, and the intrinsic absorption spectrum is red-shifted. These studies will provide early design guidance for electron sources which are based on InxGa1-xN nanowire photocathodes.