Enhanced thermoelectric properties of lightly Nb doped SrTiO3 thin films
Bhansali, Sweta (Institut Català de Nanociència i Nanotecnologia)
Khunsin, Worawut (Institut Català de Nanociència i Nanotecnologia)
Chatterjee, Arindom (Institut Català de Nanociència i Nanotecnologia)
Santiso, José (Institut Català de Nanociència i Nanotecnologia)
Abad Mayor, Begoña (Instituto de Microelectrónica de Madrid)
Martín González, Marisol (Instituto de Microelectrónica de Madrid)
Jakob, Gerhard (Johannes Gutenberg-Universität Mainz. Institut für Physik)
Sotomayor Torres, Clivia M. (Institut Català de Nanociència i Nanotecnologia)
Chávez Ángel, Emigdio (Institut Català de Nanociència i Nanotecnologia)

Date:	2019
Abstract:	Novel thermoelectric materials developed for operation at room temperature must have similar or better performance along with being as ecofriendly as those commercially used, e. g. , BiTe, in terms of their toxicity and cost. In this work, we present an in-depth study of the thermoelectric properties of epitaxial Nb-doped strontium titanate (SrTiNbO) thin films as a function of (i) doping concentration, (ii) film thickness and (iii) substrate type. The excellent crystal quality was confirmed by high resolution transmission electron microscopy and X-ray diffraction analysis. The thermoelectric properties were measured by the three-omega method (thermal conductivity) and van der Pauw method (electrical resistivity), complemented by Seebeck coefficient measurements. A maximum power factor of 8. 9 × 10 W m K and a thermoelectric figure of merit of 0. 49 were measured at room temperature in 50 nm-thick films grown on lanthanum strontium aluminate. The mechanisms behind this high figure of merit are discussed in terms of a possible two-dimensional electron gas, increase of the effective mass of the electrons, electron filtering and change in strain due to different substrates. The overall enhancement of the thermoelectric properties suggests that SrTiNbO is a very promising n-type candidate for room- to high-temperature applications.
Grants:	European Commission 645658 Ministerio de Economía y Competitividad FIS2015-70862-P Ministerio de Economía y Competitividad MAT2016-77100-C2-1-P Ministerio de Economía y Competitividad SEV-2017-0706
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Different substrates ; Doping concentration ; Lanthanum Strontium Aluminate ; Maximum power factor ; Seebeck coefficient measurement ; Thermo-Electric materials ; Thermoelectric figure of merit ; Thermoelectric properties
Published in:	Nanoscale advances, Vol. 1, Issue 9 (September 2019) , p. 3647-3653, ISSN 2516-0230

DOI: 10.1039/c9na00361d
PMID: 36133557

7 p, 2.1 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