Citrate-assisted hydrothermal synthesis of vanadium dioxide textured films with metal-insulator transition and infrared thermochromic properties

The present study reports the fast synthesis of VO2 (М1) oriented films on the r-Al2O3(012) substrates by the hydrothermal method using citric acid and vanadium (V) oxide as precursors with post deposition annealing in inert atmosphere. The effects of synthesis parameters (solution concentration and autoclave filling factor) on the films composition, morphology and electric properties are considered using XRD, Raman spectroscopy, AFM and SEM. The obtaining VO2(M1)/r-Al2O3 films show a metal-insulator transition with resistivity change of ~3.5 orders of magnitude and excellent thermochromic properties in the long-wavelength IR region. This work demonstrates a promising technique to promote the commercial implementation of VO2 as material for design of infrared (IR) switch devices.