Surface passivation effect of hydrogen and methyl on the structural and electronic properties of silicon quantum dots

Density functional calculation

M. M. Anas, Geri Kibe Gopir

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

A series of density functional theory (DFT) calculations were carried out to investigate the changes on the structural and electronic properties of silicon (Si) quantum dots (QDs) as a function of surface passivation. In particular, this study is about non-polar passivation effect of hydrogen (H) and methyl (CH3) at the surface of QDs. From geometry optimization result, it is found that clusters with reconstructed surfaces of a complete methyl passivation are possible and steric repulsion prevents full passivation of Si dots with unreconstructed surfaces. On the electronic properties point of view, it is noticed that for small nanocrystals, the presence of mini-gaps are more pronounced which can limit the non-radiative relaxation of excitons. Obviously, methyl passivation weakly affects the band gap values of silicon quantum dots, while it substantially decreases the band gap and reduced mini-gap appearance compared to hydrogen passivation Si QDs. Based on these results, it is proposed that methyl terminated quantum dots may be size selected taking advantage of the reduction on mini-gap and the localization of electron as a function of the cluster size.

Original languageEnglish
Title of host publicationMaterials Science Forum
PublisherTrans Tech Publications Ltd
Pages375-382
Number of pages8
Volume846
ISBN (Print)9783038357520
DOIs
Publication statusPublished - 2016
Event28th Regional Conference on Solid State Science and Technology, RCSSST 2014 - Cameron Highlands, Pahang, Malaysia
Duration: 25 Nov 201427 Nov 2014

Publication series

NameMaterials Science Forum
Volume846
ISSN (Print)02555476

Other

Other28th Regional Conference on Solid State Science and Technology, RCSSST 2014
CountryMalaysia
CityCameron Highlands, Pahang
Period25/11/1427/11/14

Fingerprint

Silicon
Passivation
Electronic properties
Semiconductor quantum dots
passivity
Density functional theory
Structural properties
Hydrogen
quantum dots
silicon
hydrogen
electronics
Energy gap
Excitons
Nanocrystals
nanocrystals
excitons
density functional theory
optimization
Geometry

Keywords

  • Density of state
  • DFT
  • Silicon quantum dots
  • Surface passivation effect

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering
  • Mechanics of Materials

Cite this

Surface passivation effect of hydrogen and methyl on the structural and electronic properties of silicon quantum dots : Density functional calculation. / Anas, M. M.; Gopir, Geri Kibe.

Materials Science Forum. Vol. 846 Trans Tech Publications Ltd, 2016. p. 375-382 (Materials Science Forum; Vol. 846).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Anas, MM & Gopir, GK 2016, Surface passivation effect of hydrogen and methyl on the structural and electronic properties of silicon quantum dots: Density functional calculation. in Materials Science Forum. vol. 846, Materials Science Forum, vol. 846, Trans Tech Publications Ltd, pp. 375-382, 28th Regional Conference on Solid State Science and Technology, RCSSST 2014, Cameron Highlands, Pahang, Malaysia, 25/11/14. https://doi.org/10.4028/www.scientific.net/MSF.846.375
Anas, M. M. ; Gopir, Geri Kibe. / Surface passivation effect of hydrogen and methyl on the structural and electronic properties of silicon quantum dots : Density functional calculation. Materials Science Forum. Vol. 846 Trans Tech Publications Ltd, 2016. pp. 375-382 (Materials Science Forum).
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