Origins of visible-light emissions in hydrogen-coated silicon nanocrystals: Role of passivating coating

Nacir Tit, Z. H. Yamani, J. Graham, A. Ayesh

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


We present a theoretical investigation of the electronic and optical properties of hydrogen-coated silicon nanocrystals (Si:H NCs). On one hand, the density-functional theory (DFT) is used to both calculate the total energy and relax the NCs. On a second hand, the tight-binding method, which includes the minimal sp3+-basis set within the second-nearest-neighbor interaction scheme, is applied to calculate the electronic structures, oscillator strength (OS) and recombination rate (RR) versus the NC size, coating and atomic relaxation. Three main findings are reported: (i) The quantum confinement in these NCs do follow similar rule to the case of a single-particle in a box, where the confinement energy decays in power-law with the increasing NC's size. (ii) The coating is shown to play the essential role in creation of large band-gap energy lying within the visible-light energy spectrum. (iii) The surface atomic relaxation is found to reduce the band-gap energy by about 150 meV and enhance both OS and RR. Our claims are corroborated by the available experimental data.

Original languageEnglish
Pages (from-to)2226-2237
Number of pages12
JournalJournal of Luminescence
Issue number11
Publication statusPublished - Nov 2010


  • Electronic structure of quantum dots
  • Optical properties of nanoparticles
  • Photoluminescence

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • General Chemistry
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics


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