[Research on optical property of phase transition VO2 films]

Optical transmission spectra of VO2 films on glass, fused silica, and sapphire were recorded and analyzed during heating process. Thermally induced phase transition of VO2 films occurred at a certain temperature, associated with abrupt changes in optical properties. The transition temperature and the contrast of the optical properties depended on the substrate and the deposit method used. The change in transmittance delta T at 5 microns of VO2 films deposited on sapphire by RF magnetron sputtering was 70%, and the corresponding relative change delta T/TRT was 94%. For the VO2 films deposited on glass by RF magnetron sputtering, delta T at 2.5 microns was 64.2%, and delta T/TRT was as high as 98%.