Simple method preparation for ultrathin VO2 thin film and control: nanoparticle morphology and optical transmittance

Abstract

Nanoscale morphology of vanadium dioxide (VO2) thin films can be controlled to realize smooth ultrathin crystalline films (<10 nm) with a simple way of DC sputtering. Here, crystallization annealing conditions determine whether a continuous ultrathin film or nanoparticle morphology is obtained. The experiments show that ultrathin VO2 thin films possess both a highly crystal orientation (020) and an obvious metal-insulator transition (MIT). Meanwhile, optical transmittance between the visible and near-infrared regions can be modulated by thin film thickness, and the strain in the VO2 lattice is also found to be dependent on the thin film thickness. The 8 nm thickness thin film shows that the change of resistance and visible transmittance is 2.8 orders of magnitude and 77.5%, respectively.