Vacancy filling effect in thermoelectric NbO
2015 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 27, no 11, 115501Article in journal (Refereed) Published
Using density functional theory, we have systematically explored the 1a and 1b vacancy filling in NbO (space group Pm-3m) with Nb and N, respectively, to design compounds with large Seebeck coefficients. The most dominating effect was identified for filling of 1b Wyckoff sites with N giving rise to a fivefold increase in the Seebeck coefficient. This may be understood based on the electronic structure. Nb d-nonmetal p hybridization induces quantum confinement and hence enables the enhancement of the Seebeck coefficient. This was validated by measuring the Seebeck coefficient of reactively sputtered thin films. At 800 degrees C these electrically conductive oxynitrides exhibit the Seebeck coefficient of -70 mu V K-1, which is the largest absolute value ever reported for these compounds.
Place, publisher, year, edition, pages
2015. Vol. 27, no 11, 115501
oxynitrides, thermoelectric properties, density functional theory
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:uu:diva-251416DOI: 10.1088/0953-8984/27/11/115501ISI: 000350749000009PubMedID: 25730353OAI: oai:DiVA.org:uu-251416DiVA: diva2:807441