Thickness-modulated temperature dependent optical properties of VO 2 thin films

The optical properties of VO 2 have a sharp change during metal–insulator transition, which indicates wide applications in manipulating electromagnetic waves. Here, VO 2 thin films with different thicknesses were synthesized by polymer-assisted deposition. The transmittance change trend of the VO 2 film with temperature is related with the thickness of the film, which is caused by a dramatic change of complex refractive index during phase transition. However, the transient reflectivity of 150-nm-thick VO 2 films presented abnormal change trend with temperature compared with other thinner VO 2 films, which may be related with the coexistence of multiphase VO 2 . The thickness dependent change trend of transmittance and transient reflectivity at specific light may open a new method to fabricate thickness periodic distribution metasurfaces by VO 2 film and promote the applications of VO 2 film as a metamaterial.