Polaron mobility in oxygen-deficient and lithium-doped tungsten trioxide
2015 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 92, no 16, 165119Article in journal (Refereed) Published
Electron localization and polaron mobility in oxygen-deficient as well as Li-doped monoclinic tungsten trioxide have been studied in the adiabatic limit in the framework of density functional theory. We show that small polarons formed in the presence of oxygen vacancy prefer the bipolaronicW(5+)-W5+ configuration, whereas the W6+-W4+ configuration is found to be metastable. Our calculations suggest that bipolarons are tightly bound by the vacancy and therefore largely immobile. On the contrary, polarons formed as a result of Li intercalation can be mobile; the activation energy for polaron jumping in this case varies between 98 and 124 meV depending on the crystallographic direction. The formation of W5+-W5+ bipolarons in Li-WO3 is possible. When situated along  the bipolaronic configuration is 8 meV lower in energy than two separate W5+ polarons.
Place, publisher, year, edition, pages
AMER PHYSICAL SOC , 2015. Vol. 92, no 16, 165119
Wo3 Thin-Films, Elastic Band Method, Initio Molecular-Dynamics, Minimum-Energy Paths, Oxide Films, Amorphous Wo3, Electrochromic Response, Electronic-Properties, Crystal-Structure, Room-Temperature
IdentifiersURN: urn:nbn:se:kth:diva-176963DOI: 10.1103/PhysRevB.92.165119ISI: 000363013600002ScopusID: 2-s2.0-84944811106OAI: oai:DiVA.org:kth-176963DiVA: diva2:883054
QC 201512162015-12-162015-11-132015-12-16Bibliographically approved