Strained VO2 Nanostructure Thin Films with an Unaffected Insulator-Metal Transition

Insulator-metal transition (IMT) brings some fantastic physical changes and accompanies structure phase transition (SPT) in correlated vanadium dioxide (VO2) materials. It is still in dispute whether the electron-phonon interaction induced by the lattice deformation or the electron-electron correlation drives the IMT transition. An alternative and challenging way to understand the mechanism is to separate SPT from IMT in VO2. Understanding and manipulating strain and defect in VO2 is important to regulate the IMT behavior. Herein, strained VO2 nanostructure thin films with unaffected IMT behavior are presented. The shifted phonon modes and the decreased interplanar spacing indicate the presence of the in-plane strain in VO2 nanostructure thin films. Such structural strains do not affect the transition temperature but provide a platform for the light modulation. It is believed that the unaffected IMT is beneficial for in-depth understanding of the IMT and SPT behaviors in VO2 and even the creation of advanced electronic devices.