Keywords: SiC nanowires, silicon carbide, DFT, density functional theory, phonons, electronic structure, optical vibration, nanotechnology, modelling, supercell technique, surface dangling bonds, hydrogen atoms, OH radicals, hydroxyl radicals, band gaps, passivation, phonon confinement
Electronic structure and optical vibrational modes of 3C–SiC nanowires
The electronic structure and vibrational optical modes of silicon carbide nanowires (SiCNWs) were studied using the first principles density functional theory. The nanowires were modelled along the  direction using the supercell technique passivating all the surface dangling bonds with H atoms, OH radicals and a combination of both. Results show that the full OH passivation lowers the band gap energy compared to the full H passivation owing to C–OH surface states. A shift of the highest optical vibrational modes of Si and C to lower frequency values compared to their bulk counterparts was observed in accordance with phonon confinement scheme.