Mattoni, G;
Filippetti, A;
Manca, N;
Zubko, P;
Caviglia, AD;
(2018)
Charge doping and large lattice expansion in oxygen-deficient heteroepitaxial WO3.
Physical Review Materials
, 2
(5)
, Article 053402. 10.1103/PhysRevMaterials.2.053402.
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Abstract
Tungsten trioxide (WO3) is a versatile material with widespread applications ranging from electrochromics and optoelectronics to water splitting and catalysis of chemical reactions. For technological applications, thin films of WO3 are particularly appealing, taking advantage from a high surface-to-volume ratio and tunable physical properties. However, the growth of stoichiometric crystalline thin films is challenging because the deposition conditions are very sensitive to the formation of oxygen vacancies. In this paper, we show how background oxygen pressure during pulsed laser deposition can be used to tune the structural and electronic properties of WO3 thin films. By performing x-ray diffraction and low-temperature electrical transport measurements, we find changes in the WO3 lattice volume of up to 10% concomitantly with a resistivity drop of more than five orders of magnitude at room temperature as a function of increased oxygen deficiency. We use advanced ab initio calculations to describe in detail the properties of the oxygen vacancy defect states and their evolution in terms of excess charge concentration. Our results depict an intriguing scenario where structural, electronic, optical, and transport properties of WO3 single-crystal thin films can all be purposely tuned by controlling the oxygen vacancy formation during growth.
Type: | Article |
---|---|
Title: | Charge doping and large lattice expansion in oxygen-deficient heteroepitaxial WO3 |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1103/PhysRevMaterials.2.053402 |
Publisher version: | https://doi.org/10.1103/PhysRevMaterials.2.053402 |
Language: | English |
Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
Keywords: | Science & Technology, Technology, Materials Science, Multidisciplinary, Materials Science, Tungsten-Oxide Films, Thin-Films, Chemical Expansion, Trioxide, Deposition, Srtio3, Growth, Stoichiometry, Morphology, Density |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > London Centre for Nanotechnology |
URI: | https://discovery.ucl.ac.uk/id/eprint/10053058 |
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