C-doping Anisotropy Effects on Borophene Electronic Transport.

The electronic transport anisotropy for different C-doped borophene polymorphs (β12 and χ3) was investigated theoretically combining density functional theory (DFT) and non-equilibrium Green's function (NEGF). The energetic stability analysis reveals that B atoms replaced by C is more energetically favorable for χ3 phase. We also verify a directional character of the electronic band structure on C-doped borophene for both phases. Simulated Scanning tunneling microscopy (STM) and also total density of charge confirm the directional character of the bonds. The zero bias transmission for β12 phase at E - EF = 0 shows that C-doping induces a local current confinement along the lines of doped sites. The I - V curves show that C-doping leads to an anisotropy amplification in the β12 than in the χ3. The possibility of confining the electronic current at an specific region of the C-doped systems, along with the different adsorption features of the doped sites, poses them as promising candidates to highly sensitive and selective gas sensors.