http://www.cnr.it/ontology/cnr/individuo/prodotto/ID295633

Absorption and emission of silicon nanocrystals embedded in SiC: Eliminating Fabry-Pérot interference (Articolo in rivista)

Type

Prodotto della ricerca (Classe)
Articolo in rivista (Classe)

Label

Absorption and emission of silicon nanocrystals embedded in SiC: Eliminating Fabry-Pérot interference (Articolo in rivista) (literal)

Anno

2015-01-01T00:00:00+01:00 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi

10.1063/1.4905671 (literal)

Alternative label

M. Schnabel, C. Summonte, S. A. Dyakov, M. Canino, L. López-Conesa, P. Löper, S. Janz, and P. R. Wilshaw (2015)
Absorption and emission of silicon nanocrystals embedded in SiC: Eliminating Fabry-Pérot interference
in Journal of applied physics; AIP Publishing LLC, Melville, NY 11747 (Stati Uniti d'America)
(literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori

M. Schnabel, C. Summonte, S. A. Dyakov, M. Canino, L. López-Conesa, P. Löper, S. Janz, and P. R. Wilshaw (literal)

Pagina inizio

045307-1 (literal)

Pagina fine

045307-13 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#url

http://dx.doi.org/10.1063/1.4905671 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume

117 (literal)

Rivista

Journal of applied physics (Rivista)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#pagineTotali

13 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni

1Fraunhofer-Institute for Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg, Germany 2Department of Materials, University of Oxford, Parks Rd., Oxford OX1 3PH, United Kingdom 3Consiglio Nazionale delle Richerche--Istituto per e i Microsistemi, Via Gobetti 101, 40129 Bologna, Italy 4Department of Materials and Nano Physics, School of Information and Communication Technology, Royal Institute of Technology, Electrum 229, 16440 Kista, Sweden 5MIND-IN2UB, Electronics Department, University of Barcelona, Mart?? i Franque`s 1, E-08028 Barcelona, Spain (literal)

Titolo

Absorption and emission of silicon nanocrystals embedded in SiC: Eliminating Fabry-Pérot interference (literal)

Abstract

Silicon nanocrystals embedded in SiC are studied by spectrophotometry and photoluminescence (PL) spectroscopy. Absorptivities are found to be affected by residual Fabry-P?erot interference arising from measurements of reflection and transmission at locations of different film thickness. Multiple computational and experimental methods to avoid these errors in thin film measurements, in general, are discussed. Corrected absorptivity depends on the quantity of Si embedded in the SiC but is independent of the Si crystallinity, indicating a relaxation of the k-conservation criterion for optical transitions in the nanocrystals. Tauc gaps of 1.8-2.0 and 2.12 eV are determined for Si nanoclusters and SiC, respectively. PL spectra exhibit a red-shift of ?100 nm per nm nominal Si nanocluster diameter, which is in agreement with quantum confinement but revealed to be an artifact entirely due to Fabry-P?erot interference. Several simple experimental methods to diagnose or avoid interference in PL measurements are developed that are applicable to all thin films. Corrected PL is rather weak and invariant with passivation, indicating that non-paramagnetic defects are responsible for rapid non-radiative recombination. They are also responsible for the broad, sub-gap PL of the SiC, and can wholly account for the form of the PL of samples with Si nanoclusters. The PL intensity of samples with Si nanoclusters, however, can only be explained with an increased density of luminescent defects in the SiC due to Si nanoclusters, efficient tunneling of photogenerated carriers from Si nanoclusters to SiC defects, or with emission from a-Si nanoclusters. Films prepared on Si exhibit much weaker PL than the same films prepared on quartz substrates. (literal)

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