Optical switching of au-doped VO2 sol-gel films

Pure Au and Au-doped VO2 thin films were prepared from vanadium alkoxide precursors via the sol-gel process. A solution of VO(OPri)3 was spin-coated onto silicon substrates and heat-treated under a reducing atmosphere (Ar–H2 5%). Optically transparent crystalline thin films of VO2 were obtained and characterized by X-ray diffraction (XRD), infrared (IR) absorption, and scanning electron microscopy (SEM). The AuxVO2 films exhibited the well-known metal-insulating transition and became infrared reflecting at high temperature. Their optical switching performances were carried out using a TEA CO2 laser working at 10.6 μm.