Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/49067
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Campo DC | Valor | Idioma |
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dc.contributor.author | Vieira, E. M. F. | por |
dc.contributor.author | Toudert, J. | por |
dc.contributor.author | Rolo, Anabela G. | por |
dc.contributor.author | Parisini, A. | por |
dc.contributor.author | Leitão, J. P. | por |
dc.contributor.author | Correia, M. R. | por |
dc.contributor.author | Franco, N. | por |
dc.contributor.author | Alves, E. | por |
dc.contributor.author | Chahboun, Adil | por |
dc.contributor.author | Martín-Sánchez, J. | por |
dc.contributor.author | Serna, R. | por |
dc.contributor.author | Gomes, M. J. M. | por |
dc.date.accessioned | 2018-01-08T11:13:14Z | - |
dc.date.issued | 2017-07-24 | - |
dc.date.submitted | 2017-06-11 | - |
dc.identifier.issn | 0957-4484 | por |
dc.identifier.uri | https://hdl.handle.net/1822/49067 | - |
dc.description.abstract | In this work, we report on the production of regular (SiGe/SiO2)20 multilayer structures by conventional RF-magnetron sputtering, at 350 °C. Transmission electron microscopy, scanning transmission electron microscopy, raman spectroscopy, and x-ray reflectometry measurements revealed that annealing at a temperature of 1000 °C leads to the formation of SiGe nanocrystals between SiO2 thin layers with good multilayer stability. Reducing the nominal SiGe layer thickness (t SiGe) from 3.5-2 nm results in a transition from continuous SiGe crystalline layer (t SiGe ∼ 3.5 nm) to layers consisting of isolated nanocrystals (t SiGe ∼ 2 nm). Namely, in the latter case, the presence of SiGe nanocrystals ∼3-8 nm in size, is observed. Spectroscopic ellipsometry was applied to determine the evolution of the onset in the effective optical absorption, as well as the dielectric function, in SiGe multilayers as a function of the SiGe thickness. A clear blue-shift in the optical absorption is observed for t SiGe ∼ 2 nm multilayer, as a consequence of the presence of isolated nanocrystals. Furthermore, the observed near infrared values of n = 2.8 and k = 1.5 are lower than those of bulk SiGe compounds, suggesting the presence of electronic confinement effects in the nanocrystals. The low temperature (70 K) photoluminescence measurements performed on annealed SiGe/SiO2 nanostructures show an emission band located between 0.7-0.9 eV associated with the development of interface states between the formed nanocrystals and surrounding amorphous matrix. | por |
dc.description.sponsorship | This work was partially funded by: (i) FEDER funds through the COMPETE Program and by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Project PEST-C/FIS/UI607/2011; (ii) the transnational access framework of the ANNA Eu Project (Contract No. 026134-RII3) through the funding of the ANNA_TA_UC9_RP006 proposal; (iii) UID/CTM/50025/2013 and (iv) UID/FIS/04650/2013. EMFV is grateful for financial support through the FCT and POPH of the grant SFRH/ BPD/95905/2013. The authors would like also to thank engineer José Santos for technical support at the Thin Film Laboratory. | por |
dc.language.iso | eng | por |
dc.publisher | IOP Publishing | por |
dc.relation | PEST-C/FIS/UI607/2011 | por |
dc.relation | info:eu-repo/grantAgreement/FCT/5876/147333/PT | por |
dc.relation | info:eu-repo/grantAgreement/FCT/5876/147414/PT | por |
dc.relation | info:eu-repo/grantAgreement/FCT/SFRH/SFRH%2FBPD%2F95905%2F2013/PT | por |
dc.rights | restrictedAccess | por |
dc.subject | SiGe | por |
dc.subject | multilayer structure | por |
dc.subject | RF magnetron sputtering | por |
dc.subject | TEM | por |
dc.subject | photoluminescence | por |
dc.subject | spectroscopic ellipsometry | por |
dc.subject | Raman spectroscopy | por |
dc.subject | nanocrystals | por |
dc.subject | SiGe nanocrystals | por |
dc.title | SiGe layer thickness effect on the structural and optical properties of well-organized SiGe/SiO2 multilayers | por |
dc.type | article | por |
dc.peerreviewed | yes | por |
dc.relation.publisherversion | http://iopscience.iop.org/article/10.1088/1361-6528/aa7a50 | por |
oaire.citationStartPage | 345701 | por |
oaire.citationIssue | 34 | por |
oaire.citationVolume | 28 | por |
dc.identifier.eissn | 1361-6528 | por |
dc.identifier.doi | 10.1088/1361-6528/aa7a50 | por |
dc.identifier.pmid | 28628483 | por |
dc.subject.fos | Ciências Naturais::Ciências Físicas | por |
dc.description.publicationversion | info:eu-repo/semantics/publishedVersion | por |
dc.subject.wos | Science & Technology | por |
sdum.journal | Nanotechnology | por |
Aparece nas coleções: | CDF - CEP - Artigos/Papers (with refereeing) |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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SiGe layer thickness effect on ... well-organized SiGe_SiO2 multilayers.pdf Acesso restrito! | SiGe paper 2017 | 3,6 MB | Adobe PDF | Ver/Abrir |