Enhanced optical response of hybridized VO₂/graphene films

Application of graphene as transparent electrodes is an active research area due to its excellent electrical and optical properties. Vanadium dioxide (VO₂) is an attractive material since it is a thermochromic material that undergoes a structural phase transition when heat is applied. The phase transition results in the change of electrical and optical characteristics. We report optical characteristics of hybrid materials of graphene and VO ₂. We observed a 12% improvement in infrared transmittance with VO₂ films deposited on graphene sapphire substrates compared to that of bare sapphire substrates. We also found that the phase transition temperature decreases as the number of graphene layers on the substrates increases. In the case of VO₂ films on the substrate that was coated with four layers of graphene, the mean phase transition temperature was lowered to ∼56°C.