Vanadium oxide films for optical switching and detection

Structural, electrical, and optical properties of the polycrystalline films of VO₂, V₂O₅, and mixtures of these two oxides are presented. Resistivity change by a factor larger than 10³ accompanying the semiconductor-metal phase transition in the VO₂ films is reported. A significant contrast in optical transmittance for the two phases of VO₂ is observed. High temperature resistivity and optical transmittance of the V₂O₅ films are shown. Values of the temperature coefficient of resistance in some of the VO₂ films in their semiconducting phase and in some of the V₂O₅ films are as high as 5.2 and 4% per degree Celsius, respectively. Phase switching properties of the VO₂-V₂O₅ films are described. Applications of the fabricated films include optical switches and bobmetric-type light detectors.