Preparation of Ta-Ti co-doped VO_2 polycrystal thin film with High resistance temperature coefficient and without hysteresis

摘要

Using vanadyl acetylacetonate (C_(10)H_(14)O_5V) as precursor, use Tantalum Ethoxide (Ta(OC_2H_5)_5) and Tetrabutyl titanate (C_(16)H_(36)O_4Ti)as doper, by sol-gel method fabricate Ta, Ti mono doping and Ta-Ti co-doped V_(1-x-y)Ta_xTi_yO_2 thin film. XRD spectrum indicated that the film was oriented in (011) direction. XPS 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°C, phase transition hysteresis (ΔT) by 1°C. When the doping rate is 6at.%, T_t=22°C, ΔT=1°C. Ti dopings has little affection to Tt but deduceΔT obviously. Ta-Ti co-doped V_(0.93)Ta_(0.06)Ti_(0.01)O_2 film thin films without phase transition hysteresis were also fabricated, and its TCR is as high as -7.58%/K at 25°C.