Indirect optical absorption and origin of the emission from beta-FeSi2 nanoparticles: Bound exciton (0.809 eV) and band to acceptor impurity (0.795 eV) transitions

dc.creatorLang, R
dc.creatorAmaral, L
dc.creatorMeneses, EA
dc.date2010
dc.dateMAY 15
dc.date2014-07-30T14:33:17Z
dc.date2015-11-26T16:29:43Z
dc.date2014-07-30T14:33:17Z
dc.date2015-11-26T16:29:43Z
dc.date.accessioned2018-03-28T23:10:47Z
dc.date.available2018-03-28T23:10:47Z
dc.identifierJournal Of Applied Physics. Amer Inst Physics, v. 107, n. 10, 2010.
dc.identifier0021-8979
dc.identifierWOS:000278182400033
dc.identifier10.1063/1.3391977
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/60073
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/60073
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1269799
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.descriptionCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
dc.descriptionWe investigated the optical absorption of the fundamental band edge and the origin of the emission from beta-FeSi2 nanoparticles synthesized by ion-beam-induced epitaxial crystallization of Fe+ implanted SiO2/Si(100) followed by thermal annealing. From micro-Raman scattering and transmission electron microscopy measurements it was possible to attest the formation of strained beta-FeSi2 nanoparticles and its structural quality. The optical absorption near the fundamental gap edge of beta-FeSi2 nanoparticles evaluated by spectroscopic ellipsometry showed a step structure characteristic of an indirect fundamental gap material. Photoluminescence spectroscopy measurements at each synthesis stage revealed complex emissions in the 0.7-0.9 eV spectral region, with different intensities and morphologies strongly dependent on thermal treatment temperature. Spectral deconvolution into four transition lines at 0.795, 0.809, 0.851, and 0.873 eV was performed. We concluded that the emission at 0.795 eV may be related to a radiative direct transition from the direct conduction band to an acceptor level and that the emission at 0.809 eV derives from a recombination of an indirect bound exciton to this acceptor level of beta-FeSi2. Emissions 0.851 and 0.873 eV were confirmed to be typical dislocation-related photoluminescence centers in Si. From the energy balance we determined the fundamental indirect and direct band gap energies to be 0.856 and 0.867 eV, respectively. An illustrative energy band diagram derived from a proposed model to explain the possible transition processes involved is presented. (C) 2010 American Institute of Physics. [doi:10.1063/1.3391977]
dc.description107
dc.description10
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.descriptionCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.descriptionCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
dc.languageen
dc.publisherAmer Inst Physics
dc.publisherMelville
dc.publisherEUA
dc.relationJournal Of Applied Physics
dc.relationJ. Appl. Phys.
dc.rightsaberto
dc.sourceWeb of Science
dc.subjectSemiconducting Iron Disilicide
dc.subjectBeam Synthesized Beta-fesi2
dc.subject1.5 Mu M
dc.subjectPolycrystalline Beta-fesi2
dc.subjectSingle-crystals
dc.subjectThin-films
dc.subjectSilicon
dc.subjectPhotoluminescence
dc.subjectLuminescence
dc.subjectSi(100)
dc.titleIndirect optical absorption and origin of the emission from beta-FeSi2 nanoparticles: Bound exciton (0.809 eV) and band to acceptor impurity (0.795 eV) transitions
dc.typeArtículos de revistas


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