Insulator to metal transition in VO_2 M1+B phase on silicon substrate

摘要

Here we report on X-ray diffraction (XRD), temperature dependent resistivity and Raman measurements of pulsed laser deposition (PLD) grown thin films on Si substrate. XRD confirms coexistence of two, the VO_2 M1 and the VO_2 B, monoclinic phases at room temperature. Resistivity measurement exhibits a transition from low temperature insulating phase to high temperature metallic phase, indicating major contribution of the VO_2 M1 phase. Insulator to metal transition (IMT) is found to occur at ～328 K which is ～12 K lower compared to bulk VO_2. Raman measurements confirm the first order structural phase transition, from low temperature monoclinic to high temperature rutile, concomitant with the IMT. Lowering of the transition temperature in our thin film compared to bulk VO_2 is due to strain in the thin film.