Controlled growth of VO₂ Nanowires by direct conversion of V₂O₅solution film

Vanadium dioxide is known to exhibit fascinating properties due to its phase transition from insulating to metallic phase at 340 K. Effectively growing single-crystal VO₂ nanowires has been difficult to realize in a controlled, repeatable way. Through the use of a chemical vapor deposition using solutions of V₂O₅, we realized a consistent growth of single crystals with their size ranging from nanowires to microbeams. A comprehensive understanding of the growth mechanism has also been obtained. With combined probing techniques, including an Enhanced Darkfield Optical Microscopy, Atomic Force Microscopy, and Raman Microspectroscopy, we captured the dynamics of growth, along with the stoichiometry and crystal structure for nanocrystals at different growth stages. We revealed that the growth starts with the vaporization of V₂O₅, followed by dense seed nucleation on the substrate, and then the growing of large crystals as a result of consuming neighboring seeds.
The new method of VO₂ nanowires growth based on V₂O₅ film provides a simpler and more economical solution for their application in industry.