Microstructure and properties of $VO{_2}$ thin films deposited by MOCVD from vanadyl acetylacetonate

Sahana, MB and Dharmaprakash, MS and Shivashankar, SA (2002) Microstructure and properties of $VO{_2}$ thin films deposited by MOCVD from vanadyl acetylacetonate. In: Journals of Materials Chemistry, 12 (2). pp. 333-338.

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Abstract

Thin films of vanadium dioxide have been deposited on glass by low pressure metal-organic chemical vapour deposition using the beta-diketonate complex, vanadyl acetylacetonate, as the precursor. It is found that nearly monophasic, monoclinic VO2(M) films are formed in the narrow temperature range 475-520 degreesC, films formed outside this range comprising significant proportions of other vanadium oxide phases beside VO2(M). The microstructure of these well-crystallized films varies significantly with temperature in this range. Films grown at 475 degreesC are dense and have a very strong (200) orientation. At 520 degreesC, films are somewhat porous, and display little preferred orientation. Film microstructure influences the semiconductor-metal transition noticeably. Films deposited at 475 degreesC have a large change in resistance at 66 degreesC, and display a small temperature hysteresis in the transition. The transition temperature in films grown at 520 degreesC is higher (72 degreesC), whereas the change in resistance is smaller and the hysteresis larger. An attempt has been made to understand the unusual microstructure of VO2 films grown on glass substrates. The variation in the phase transition characteristics is interpreted in terms of the observed film microstructure. The thermal properties of the CVD precursor are also reported.

Item Type:	Journal Article
Publication:	Journals of Materials Chemistry
Publisher:	Royal Society of Chemistry
Additional Information:	Copyright of this article belongs to Royal Society Chemistry.
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	19 Nov 2009 08:12
Last Modified:	19 Sep 2010 04:59
URI:	http://eprints.iisc.ac.in/id/eprint/18021

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