Silicon nanowire band gap modification

Michael Nolan, Sean O'Callaghan, Giorgos Fagas, James C. Greer, Thomas Frauenheim

Research output: Journal PublicationArticlepeer-review

210 Citations (Scopus)


Band gap modification for small-diameter (∼1 nm) silicon nanowires resulting from the use of different species for surface termination is investigated by density functional theory calculations. Because of quantum confinement, small-diameter wires exhibit a direct band gap that increases as the wire diameter narrows, irrespective of surface termination. This effect has been observed in previous experimental and theoretical studies for hydrogenated wires. For a fixed cross-section, the functional group used to saturate the silicon surface significantly modifies the band gap, resulting in relative energy shifts of up to an electronvolt. The band gap shifts are traced to details of the hybridization between the silicon valence band and the frontier orbitals of the terminating group, which is in competition with quantum confinement.

Original languageEnglish
Pages (from-to)34-38
Number of pages5
JournalNano Letters
Issue number1
Publication statusPublished - Jan 2007
Externally publishedYes

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry (all)
  • Materials Science (all)
  • Condensed Matter Physics
  • Mechanical Engineering


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