Tailoring Epitaxial VO<sub>2</sub> Thin Films with Tunable Properties via Spray Pyrolysis
Ardak Ainabаyev, Brian Walls, Daniel Casey, David Caffrey, Daragh Mullarkey, Amy McGlinchey, Amit Khare, Alexander Tikhonov, Cansu Ilhan, Darragh Brennan, Sarah McCormack, I. V. Shvets
Abstract
High Resolution Image Download MS PowerPoint Slide Significant advancements have been made in the past few decades in the precise control of VO 2 synthesis, enabling the creation of structures with diverse morphologies and distinct phase transition properties. Existing synthesis methods used in research settings are often inadequate for large-scale production, particularly concerning high-quality VO 2 thin films. Addressing these synthesis obstacles is crucial to unlocking the full potential of VO 2 and harnessing its multifunctional properties for a broad range of practical applications. In this study, we highlight the low-cost, nonvacuum, and high-yield spray pyrolysis technique as a promising method for fabricating high-quality VO 2 thin films. We successfully synthesized high-quality epitaxial VO 2 thin films on a c -plane Al 2 O 3 substrate using spray pyrolysis. Two approaches were employed: direct growth in a nitrogen–oxygen environment and growth of V 2 O 3 in a nitrogen atmosphere, followed by postannealing in a nitrogen–oxygen mix. Both methods yielded relatively high-quality VO 2 films with metal–insulator transition properties comparable to those achieved by more sophisticated growth techniques. However, we observed some differences in the electrical and structural properties between the two fabrication approaches. These findings highlight the potential of spray pyrolysis as a cost-effective and scalable technique for the production of high-quality functional VO 2 thin films, providing an alternative to conventional growth methods. Optimization of growth parameters and processes is essential for achieving the desired electrical and structural properties in spray pyrolysis-synthesized VO 2 films.