Study on Phase Transition Property of Tungsten-doped Vanadium Dioxide Thin Film at Terahertz Range

Vanadium dioxide and tungsten-doped (W-doped) vanadium dioxide thin films deposited by aqueous Sol-Gel method were characterized with several different techniques (i.e. X-ray photoelectron spectroscope, atomic force microscope, X-ray diffraction), to determine their morphology and microstructure. Their metal-to-insulator (MIT) phase transition behavior in infrared spectral region (λ=4 μm) and terahertz (THz) spectral region (0.3–1.0 THz) were observed respectivele. The results demonstrate that the transmittance of W-doped VO 2 film at room temperature is visibly lower than that of undoped VO 2 film in both infrared and terahertz spectral region. The transition temperature of W-doped VO 2 film is also lower than that of undoped VO 2 film in the THz range. The MIT and structural phase transition (SPT) are observed during the phase transition of VO 2 and W-doped VO 2 , and an obvious change of peak position occurs in W-doped VO 2 film.