Optical Analysis of Oxygen Self-Diffusion in Ultrathin CeO2 Layers at Low Temperatures
Neuderth, Paula (Justus Liebig University Giessen)
Hille, Pascal (University Bremen. Institute of Solid State Physics)
Martí-Sánchez, Sara (Institut Català de Nanociència i Nanotecnologia)
De La Mata, Maria (Institut Català de Nanociència i Nanotecnologia)
Coll, Mariona (Institut de Ciència de Materials de Barcelona)
Arbiol i Cobos, Jordi (Institut Català de Nanociència i Nanotecnologia)
Eickhoff, Martin (University of Bremen. Institut für Festkörperphysik)

Date:	2018
Abstract:	An optical in situ strategy for the analysis of oxygen diffusion in ultrathin ceria layers with a thickness of 2-10 nm at temperatures between 50 and 200 °C is presented, which allows for the determination of diffusion coefficients. This method is based on the sensitivity of the photoluminescence (PL) intensity of InGaN nanowires to adsorbed oxygen. The oxygen diffusion through an ultrathin CeO coating deposited on the InGaN nanowires is monitored by analyzing the transient PL behavior of the InGaN nanowires, which responds to changes of the oxygen concentration in the environment when the corresponding oxygen concentration is established at the CeO/InGaN interface due to diffusion through the coating. Quantitative evaluation of the oxygen diffusion in CeO based on a model considering Langmuir Adsorption and recombination yields a diffusion coefficient D of (2. 55 ± 0. 05) × 10 cm s at a temperature of 100 °C. Temperature-dependent measurements reveal an Arrhenius type behavior of D with an activation energy of (0. 28 ± 0. 04) eV. In contrast, no oxygen diffusion is detected for an ultrathin layer (≥5 nm) of AlO, which is known as a poor oxygen ion conductor within the analyzed temperature regime.
Grants:	Ministerio de Economía y Competitividad RYC-2013-12448 Ministerio de Economía y Competitividad SEV-2015-0496 Ministerio de Economía y Competitividad MAT2017-83169-R Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-327 Ministerio de Economía y Competitividad ENE2017-85087-C3 Ministerio de Economía y Competitividad SEV-2013-0295 European Commission 654360
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió sotmesa a revisió
Subject:	Atomic layer deposition ; CeO2 ; InGaN nanowires ; Nanophotonic chemical sensors ; Oxygen diffusion
Published in:	Advanced Energy Materials, Vol. 8, Issue 29 (October 2018) , art. 1802120, ISSN 1614-6840

DOI: 10.1002/aenm.201802120

Preprint 17 p, 1.5 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles