Dixon, Sebastian C.;
(2020)
Chemical and physical vapour deposition of optoelectronic metal oxide thin films.
Doctoral thesis (Eng.D), UCL (University College London).
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Abstract
Metal oxide thin films feature prominently in virtually every optoelectronic device including photovoltaics, for harnessing solar energy, and LED displays, as seen ubiquitously in every smartphone, television, smartwatch, information display, etc.. These materials perform an important function in such devices as transparent electrodes enabling the flow of current through the device whilst permitting incident or emitted light to pass freely and uncoloured between the central optoelectronic element and the external medium. Such materials are known as transparent conducting oxides (TCOs), and owe their transparency to a wide optical band gap exceeding the energy of visible photons (> 3.1 eV), and their electrical conductivity to a sufficiently high free electron density and mobility. Free electrons in these materials originate from crystal defects, which can be deliberately introduced by doping. Transition metal (TM) dopants have recently come to light as enabling greater electron mobility in TCOs compared to traditional main- group dopants, while widening their optical transparency window into both the UV and IR. The commercial standard TCO material for most applications is Sn-doped In2O3, therefore the first objective of this thesis is to explore and compare to Sn some transition metal dopants (Zr, Hf, Mo) for In2O3 in terms of electronic and optical behaviour. The commercial supply risk associated with indium, being a naturally scarce element, leads to the second objective, which is to explore TM doping of SnO2 using Ta. This is carried out using commercial scale-up syntheses via atmospheric-pressure chemical vapour deposition (APCVD) with a view to creating a more competitive indium-free TCO. Finally, gallium(III) antimonates (Ga2xSb2-2xO4) are explored via APCVD as ternary indium- free, wide-bandgap host matrices for TCO and TFT applications.
Type: | Thesis (Doctoral) |
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Qualification: | Eng.D |
Title: | Chemical and physical vapour deposition of optoelectronic metal oxide thin films |
Event: | UCL (University College London) |
Open access status: | An open access version is available from UCL Discovery |
Language: | English |
Additional information: | Copyright © The Author 2020. Original content in this thesis is licensed under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) Licence (https://creativecommons.org/licenses/by/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
Keywords: | Chemical vapour deposition, Chemical vapor deposition, metal oxides, tco, transparent conductor, thin films, cvd, apcvd |
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 > Dept of Chemistry |
URI: | https://discovery.ucl.ac.uk/id/eprint/10093653 |
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