Hydrothermal synthesis of high quality free-standing VO2(B) thin film and its thermal resistance characteristics

Vanadium oxide is a type of material with high temperature coefficient of resistance (TCR) for bolometric infrared detection. In this letter, the effects of growth conditions of B-phase crystalline VO2, including reaction temperature, reaction time and quantities of precursors, were systematically investigated. Free-standing VO2(B) thin film composed of nano-sheets stacking on the (0 0 1) plane was prepared. The in-plane and out-of-plane TCRs were measured. A superior in-plane TCR of −3.0%/K was observed at room temperature, while the out-of-plane TCR only was −1.7%/K. We further showed that the I-V behavior of VO2(B) was voltage-dependent, and its possible origin was discussed.