Low temperature fabrication of high-performance VO2 film via embedding low vanadium buffer layer

Abstract

Vanadium dioxide (VO2), which can initiate an automatic reversible metal-to-insulator transition (MIT) from tetragonal to monoclinic structure at the transition temperature (Tc) of 68 °C, is a promising candidate to realize electronic devices due to its dramatic changes in electrical resistivity through MIT. Moreover, the application of VO2 on modulation devices requires a narrow hysteresis width associated with a significant change in its electronic properties, which is quite challenging in VO2 films fabricated by magnetron sputtering, besides, the high preparation temperature around 400 °C also hinders the further industrial production of VO2 films. In this paper, by adding a simple and easy-to-obtain low-valence vanadium buffer layer between the substrate and the VO2 layer, high performance VO2 films with electrical phase transition close to four orders of magnitude and loop width less than 5 °C are obtained. Meanwhile, the annealing temperature of the fabricating process is decreased to only 320 °C, which is 80 °C lower than the ordinary preparation temperature and significantly reducing energy consumption and manufacturing difficulty. Such enhanced performance will benefit the publicity and application for VO2-based modulation devices.