Synthesis and properties of Mo and W ions co-doped porous nano-structured VO2 films by sol-gel process

Porous nano-structured vanadium dioxide (VO2) films doped with Mo and W ions had been synthesized by sol gel process by employing a sol containing ammonium molybdate and ammonium tungstate with the addition of cetyltrimethyl ammonium bromide (CTAB). The effects of molybdenum and tungsten co-doping and CTAB addition on the structure, morphologies, crystalline and optical properties of VO2 films were investigated systematically in this study. The composition and microstructure were detected by X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. The Mo and W ions co-doped porous nano-structured VO2 films showed excellent infrared transmittance (nearly 70 %), large transmittance difference (55 %) before and after the phase transition, low transition temperature (35 A degrees C), wide hysteresis width (22 A degrees C) and fast phase transition. The results suggest that such Mo and W ions co-doped porous nano-structured VO2 film is an ideal fundamental material for optical data storage.