Coexistent VO(2) (M) and VO(2) (B) Polymorphous Thin Films with Multiphase-Driven Insulator–Metal Transition

Reversible insulator–metal transition (IMT) and structure phase change in vanadium dioxide (VO(2)) remain vital and challenging with complex polymorphs. It is always essential to understand the polymorphs that coexist in desired VO(2) materials and their IMT behaviors. Different electrical properties and lattice alignments in VO(2) (M) and VO(2) (B) phases have enabled the creation of versatile functional devices. Here, we present polymorphous VO(2) thin films with coexistent VO(2) (M) and VO(2) (B) phases and phase-dependent IMT behaviors. The presence of VO(2) (B) phases may induce lattice distortions in VO(2) (M). The plane spacing of (011)(M) in the VO(2) (M) phase becomes widened, and the V-V and V-O vibrations shift when more VO(2) (B) phase exists in the VO(2) (M) matrix. Significantly, the coexisting VO(2) (B) phases promote the IMT temperature of the polymorphous VO(2) thin films. We expect that such coexistent polymorphs and IMT variations would help us to understand the microstructures and IMT in the desired VO(2) materials and contribute to advanced electronic transistors and optoelectronic devices.