Optical properties of thin films of amorphous vanadium oxides

The results of an experimental investigation of the optical properties of anodic vanadium oxide films are presented. It is shown that films of different phase composition (VO₂, V₂O₅, or a mixture of two phases) can be obtained, depending on the oxidation regime, and that the absorption and transmission spectra are modified significantly in accordance. The optical properties of the oxides, whose composition is close to stoichiometric vanadium dioxide, demonstrate the occurrence of a metal-semiconductor phase transition in the amorphous films. The results presented are important both from the standpoint of technical applications of thin film systems based on anodic vanadium oxides and for more detailed understanding of the physical mechanism of the metal-semiconductor phase transition and the influence of structural disorder on the transition. Pis’ma Zh. Tekh. Fiz. 25, 81–87 (April 26, 1999)