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dc.contributor.authorBruzzi, Mara
dc.contributor.authorMori, Riccardo
dc.contributor.authorBaldi, Andrea
dc.contributor.authorCarnevale, Ennio
dc.contributor.authorCavallaro, Alessandro
dc.contributor.authorScaringella, Monica
dc.date.accessioned2018-03-21T18:47:09Z
dc.date.available2018-03-21T18:47:09Z
dc.date.issued2018-01-05
dc.identifier.citationThermally Stimulated Currents in Nanocrystalline Titania 2018, 8 (2):13 Nanomaterialsen
dc.identifier.issn2079-4991
dc.identifier.doi10.3390/nano8010013
dc.identifier.urihttp://hdl.handle.net/10150/627084
dc.description.abstractA thorough study on the distribution of defect-related active energy levels has been performed on nanocrystalline TiO2. Films have been deposited on thick-alumina printed circuit boards equipped with electrical contacts, heater and temperature sensors, to carry out a detailed thermally stimulated currents analysis on a wide temperature range (5-630 K), in view to evidence contributions from shallow to deep energy levels within the gap. Data have been processed by numerically modelling electrical transport. The model considers both free and hopping contribution to conduction, a density of states characterized by an exponential tail of localized states below the conduction band and the convolution of standard Thermally Stimulated Currents (TSC) emissions with gaussian distributions to take into account the variability in energy due to local perturbations in the highly disordered network. Results show that in the low temperature range, up to 200 K, hopping within the exponential band tail represents the main contribution to electrical conduction. Above room temperature, electrical conduction is dominated by free carriers contribution and by emissions from deep energy levels, with a defect density ranging within 10(14)-10(18) cm(-3), associated with physio- and chemi-sorbed water vapour, OH groups and to oxygen vacancies.
dc.language.isoenen
dc.publisherMDPI AGen
dc.relation.urlhttp://www.mdpi.com/2079-4991/8/1/13en
dc.rights© 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.en
dc.rights.urihttps://creativecommons.org/licenses/by/4.0/
dc.subjectthermally stimulated currentsen
dc.subjectphotocurrenten
dc.subjecttitanium dioxideen
dc.subjecthoppingen
dc.subjectnanoporous filmen
dc.subjectdesorption currenten
dc.subjectchemisorbed currenten
dc.titleThermally Stimulated Currents in Nanocrystalline Titaniaen
dc.typeArticleen
dc.contributor.departmentUniv Arizona, LBT Observen
dc.identifier.journalNanomaterialsen
dc.description.noteOpen access journal.en
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en
dc.eprint.versionFinal published versionen
refterms.dateFOA2018-06-12T21:22:39Z
html.description.abstractA thorough study on the distribution of defect-related active energy levels has been performed on nanocrystalline TiO2. Films have been deposited on thick-alumina printed circuit boards equipped with electrical contacts, heater and temperature sensors, to carry out a detailed thermally stimulated currents analysis on a wide temperature range (5-630 K), in view to evidence contributions from shallow to deep energy levels within the gap. Data have been processed by numerically modelling electrical transport. The model considers both free and hopping contribution to conduction, a density of states characterized by an exponential tail of localized states below the conduction band and the convolution of standard Thermally Stimulated Currents (TSC) emissions with gaussian distributions to take into account the variability in energy due to local perturbations in the highly disordered network. Results show that in the low temperature range, up to 200 K, hopping within the exponential band tail represents the main contribution to electrical conduction. Above room temperature, electrical conduction is dominated by free carriers contribution and by emissions from deep energy levels, with a defect density ranging within 10(14)-10(18) cm(-3), associated with physio- and chemi-sorbed water vapour, OH groups and to oxygen vacancies.


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© 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.
Except where otherwise noted, this item's license is described as © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.