First-principles investigation of strain effects on the energy gaps in silicon nanoclusters

Xihong Peng, A. Alizadeh, N. Bhate, K. K. Varanasi, S. K. Kumar, S. K. Nayak

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

First-principles density functional calculations were performed to study strain effects on the energy gaps in silicon nanoclusters with diameter ranging from 0.6 to 2nm. Hydrostatic and non-hydrostatic strains have been found to affect the energy gaps differently. For the same strain energy density, non-hydrostatic strain leads to a significantly larger change in the energy gap of silicon clusters compared to that of the hydrostatic strain case. In contrast, hydrostatic and non-hydrostatic strain effects on the energy gaps of bulk Si or larger size Si quantum dots are comparable. Non-hydrostatic strains break the tetrahedral bonding symmetry in silicon, resulting in significant variation in the energy gaps due to the splitting of the degenerate orbitals in the clusters. Our results suggest that the combination of energy gaps and strains permits the engineering of photoluminescence in silicon nanoclusters and offers the possibility of designing novel optical devices and chemical sensors.

Original languageEnglish (US)
Article number266212
JournalJournal of Physics Condensed Matter
Volume19
Issue number26
DOIs
StatePublished - Jul 4 2007
Externally publishedYes

Fingerprint

Nanoclusters
Silicon
nanoclusters
Energy gap
silicon
hydrostatics
Optical devices
Strain energy
Chemical sensors
Semiconductor quantum dots
flux density
Density functional theory
quantum dots
engineering
Photoluminescence
photoluminescence
orbitals
sensors
symmetry

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

First-principles investigation of strain effects on the energy gaps in silicon nanoclusters. / Peng, Xihong; Alizadeh, A.; Bhate, N.; Varanasi, K. K.; Kumar, S. K.; Nayak, S. K.

In: Journal of Physics Condensed Matter, Vol. 19, No. 26, 266212, 04.07.2007.

Research output: Contribution to journalArticle

Peng, Xihong ; Alizadeh, A. ; Bhate, N. ; Varanasi, K. K. ; Kumar, S. K. ; Nayak, S. K. / First-principles investigation of strain effects on the energy gaps in silicon nanoclusters. In: Journal of Physics Condensed Matter. 2007 ; Vol. 19, No. 26.
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