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 sol-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. 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 (Tt) by 7.8°C, phase transition hysteresis (ΔT) by 1°C. When the doping rate is 6at.%, Tt=22°C, ΔT=1°C. Ti dopings has little affection to Tt but deduce ΔT 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°C.
Xiaoming Sang, Pengcheng Wang, Liqun Ai, Yungang Li and Jinglong Bu
M. P. Jiang et al., "Preparation of Ta-Ti Co-Doped VO2 Polycrystal Thin Film with High Resistance Temperature Coefficient and without Hysteresis", Advanced Materials Research, Vols. 284-286, pp. 2177-2181, 2011