Details

Autor(en) / Beteiligte

• Rosso, E.F.
• Baierle, R.J.
• Orellana, W.
• Miwa, R.H.

Titel

Hydrogen-induced nanotunnel structure on the C-terminated β-SiC(001)-c(2×2) surface investigated by ab-initio calculations

Ist Teil von

• Applied surface science, 2015-12, Vol.357, p.1753-1757

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2015

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •β-SiC(001) surface.•Hydrogenation.•DFT calculations – PBE and HSE06 functional for the exchange correlation term.•Nanotunnel formation.•Electronic confinement. The structural and electronic properties of pristine and H-passivated C-terminated β-SiC(001)-c(2×2) surface are addressed by ab initio calculations. Here, we verify the formation of C chains composed by double-bonded dimers rows (CC), separated by triple-bonded bridged dimers (CC). The surface states near the bandgap are confined along the CC dimer rows, with no electronic contribution from the CC bridged dimers. After hydrogenation, the C-chains are strongly modified, forming subsurface voids or nanotunnel (NT) structures. By considering a plausible set of energy release steps for increasing hydrogenation, we obtain a C-rich NT ruled by the CC dimer rows. Somewhat similar to that recently reported on the Si-rich termination, but 0.8eV lower in energy. The electronic band structures of both Si-rich and C-rich NTs have been examined within the hybrid HSE06 functional, which are compared with those previously reported using a semilocal functional.