Figure 6. Optical Properties of gold doped vanadium dioxide films prepared using the hybrid method.

The figure graphically dipicts the various optical properties of the gold / vanadium dioxide nanocomposite thin films. The top left figure shows the change in transmission on passing the transition temperature. This is similar to normal vanadium dioxide thin films.

The bottom left figure shows the change in reflectance. The cold state now has a much higher reflectance than seen previously due to the inclusion of gold nano-particles into the films.

The right hand side figures show different ways of measuring the transition temperature. The top right figure shows a change in transmission at a fixed infra-red wavelength (2500 nm). The bottom right shows the change in surface plasmon resonance center plotted against temperature. The surface plasmon resonance centre changes as the dielectric constant for the host matrix (the vanadium dioxide) changes with the temperature induced phase transition. As such gold / vanadium dioxide nano-composites have potential for use as optical switches.