Bismuth alloying properties in GaAs nanowires

•A typical model of Ga31As31 nanowires is introduced for its reasonable band gap.•The band gap of GaAs1−xBix shrinks clearly with the increasing Bi concentration.•The band edge shifts when spin–orbit coupling (SOC) is considered.•The insertion of Bi atom leads to hybridization of Ga/As/Bi p states.

First-principles calculations have been performed to investigate the structural, electronic and optical properties of bismuth alloying in GaAs nanowires. A typical model of Ga31As31 nanowires is introduced for its reasonable band gap. The band gap of GaAs1−xBix shrinks clearly with the increasing Bi concentration and the band edge shifts when spin–orbit coupling (SOC) is considered. The insertion of Bi atom leads to hybridization of Ga/As/Bi p states which contributes a lot around Fermi level. Scissor effect is involved. The optical properties are presented, including dielectric function, optical absorption spectra and reflectivity, which are also varied with the increasing of Bi concentrations.

Graphical abstractTop view of Bi-doped GaAs nanowires. Ga, As, and Bi atoms are denoted with grey, purple and red balls, respectively.Figure optionsDownload full-size imageDownload as PowerPoint slide