Flexible VO2/Mica thin films with excellent phase transition properties fabricated by RF magnetron sputtering

Abstract

Integration of vanadium dioxide (VO2) on flexible substrates can realize flexible devices which can modulate the photoelectric response triggered by temperature, electric field, laser, etc. But the preparation of high quality flexible films is still blocked due to the high-temperature condition for VO2 growth. In this paper, a one-step procedure was proposed to prepare VO2 thin films on low-priced natural mica substrate by radio frequency (RF) reactive magnetron sputtering with a pure V target in an atmosphere of Ar/O2 gas mixture. Through optimizing the deposition temperature and thickness systematically, a high performance flexible VO2 film was obtained. It demonstrated large resistance change of around 4.8 orders of magnitude, and giant terahertz (THz) switching ratio of around 86.1% across the phase transition. Moreover, the VO2/Mica flexible film remained stable phase transition characteristic during the bending flexibility measurement. This work provides an alternative way to fabricate flexible VO2 film and makes it a candidate for the applications in flexible oxide electronics.