Effect of the surrounding oxide on the photoabsorption spectra of Si nanocrystals

dc.contributorAalto-yliopistofi
dc.contributorAalto Universityen
dc.contributor.authorKoponen, Laura
dc.contributor.authorTunturivuori, Lasse O.
dc.contributor.authorPuska, Martti J.
dc.contributor.authorNieminen, Risto M.
dc.contributor.departmentDepartment of Applied Physics
dc.date.accessioned2018-05-22T14:46:48Z
dc.date.available2018-05-22T14:46:48Z
dc.date.issued2009-06-26
dc.description.abstractA systematic study of the optical absorption of small silicon nanocrystals (Si-NCs) embedded in silicon dioxide is performed using real-time time-dependent density-functional theory. The modeled Si-NCs contain up to 47 Si atoms with the surrounding oxide being described by a shell of SiO2. The oxide-embedded Si-NCs exhibit absorption spectra that differ significantly from the spectra of the hydrogen-passivated Si-NCs. In particular, the minimum absorption energy is found to decrease when the Si-NCs are exposed to dioxide coating. Unexpectedly, the absorption energy of the oxide-embedded Si-NCs remains approximately constant for core sizes down to 17 atoms, whereas the absorption energy of the hydrogen-passivated Si-NCs increases with decreasing crystal size. This trend suggests a different mechanism for producing the lowest-energy excitations in these two cases.en
dc.description.versionPeer revieweden
dc.format.extent6
dc.format.extent1-6
dc.format.mimetypeapplication/pdf
dc.identifier.citationKoponen , L , Tunturivuori , L O , Puska , M J & Nieminen , R M 2009 , ' Effect of the surrounding oxide on the photoabsorption spectra of Si nanocrystals ' , Physical Review B , vol. 79 , no. 23 , 235332 , pp. 1-6 . https://doi.org/10.1103/PhysRevB.79.235332en
dc.identifier.doi10.1103/PhysRevB.79.235332
dc.identifier.issn1098-0121
dc.identifier.issn1550-235X
dc.identifier.otherPURE UUID: bcc1facb-f2d5-47c8-bbb0-ea21dd4ad616
dc.identifier.otherPURE ITEMURL: https://research.aalto.fi/en/publications/bcc1facb-f2d5-47c8-bbb0-ea21dd4ad616
dc.identifier.otherPURE FILEURL: https://research.aalto.fi/files/14662859/PhysRevB.79.235332.pdf
dc.identifier.urihttps://aaltodoc.aalto.fi/handle/123456789/31135
dc.identifier.urnURN:NBN:fi:aalto-201805222575
dc.language.isoenen
dc.relation.ispartofseriesPhysical Review Ben
dc.relation.ispartofseriesVolume 79, issue 23en
dc.rightsopenAccessen
dc.subject.keywordphotoluminiscence
dc.subject.keywordSi nanocrystals
dc.subject.keywordtime-dependent density functional theory
dc.titleEffect of the surrounding oxide on the photoabsorption spectra of Si nanocrystalsen
dc.typeA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessäfi
dc.type.versionpublishedVersion
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