Preparation of Ta-Ti co-doped VO2 polycrystal thin film with High resistance temperature coefficient and without hysteresis

Using vanadyl acetylacetonate (C10H14O5V) as precursor, use Tantalum Ethoxide (Ta(OC2H5)(5)) and Tetrabutyl titanate (C16H36O4Ti)as doper, by sot-gel method fabricate Ta, Ti mono doping and Ta-Ti co-doped V1-x-yTaxTiyO2 thin film. XRD spectrum indicated that the film was oriented in (011) direction. X PS results indicated the valence state of V, Ta, Ti in the film is +4, at all. While Ta mono doping, single 1at.%Ta can deduce the phase transiton temperature (T-t) by 7.8 degrees C, phase transition hysteresis (Delta T) by 1 degrees C. When the doping rate is 6at.%, T-t=22 degrees C, Delta T=1 degrees C. Ti dopings has little affection to T-t but deduce Delta T obviously. Ta-Ti co-doped V0.93Ta0.06Ti0.01O2 film thin films without phase transition hysteresis were also fabricated, and its TCR is as high as -7.58%/K at 25 degrees C.