title: Continuous Tuning of Phase Transition Temperature in VO2Thin Films on c-Cut Sapphire Substrates via Strain Variation.
abstract: Vanadium dioxide (VO2) thin films with controlled thicknesses are deposited on c-cut sapphire substrates with Al-doped ZnO (AZO) buffer layers by pulsed laser deposition. The surface roughness of AZO buffer layers is varied by controlling oxygen pressure during growth. The strain in the VO2lattice is found to be dependent on the VO2thickness and the VO2/AZO interface roughness. The semiconductor-to-metal transition (SMT) properties of VO2thin films are characterized and the transition temperature (Tc) is successfully tuned by the VO2thickness as well as the VO2/AZO interface roughness. It shows that the Tcof VO2decreases with the decrease of film thickness or VO2/AZO interface roughness. Other SMT properties of the VO2films are maintained during the Tctuning. The results suggest that the strain tuning induced by AZO buffer provides an effective approach for tuning Tcof VO2continuously.
authors.forename: Jie
authors.identifier: http://orcid.org/0000-0003-0742-3498
authors.initials: J
authors.lastname: Jian
authors.affiliation: School of Materials Engineering, Purdue University , West Lafayette, Indiana 47907-2045, United States.
authors.forename: Xuejing
authors.initials: X
authors.lastname: Wang
authors.forename: Leigang
authors.initials: L
authors.lastname: Li
authors.forename: Meng
authors.initials: M
authors.lastname: Fan
authors.forename: Wenrui
authors.initials: W
authors.lastname: Zhang
authors.forename: Jijie
authors.initials: J
authors.lastname: Huang
authors.affiliation: School of Materials Engineering, Purdue University , West Lafayette, Indiana 47907-2045, United States.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Qi
authors.affiliation: School of Materials Engineering, Purdue University , West Lafayette, Indiana 47907-2045, United States.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Wang
keywords: VO2; film thickness; interface roughness; phase transition temperature; strain tuning