Thermochromic, threshold switching, and optical properties of Cr-doped VO2 thin films

Abstract In this paper, undoped and Cr-doped VO2 thin films were fabricated and deposited onto Al2O3 substrates using a sol-gel method. Then, the effects of Cr-doping on the thermochromic, and optical properties of the thin films were investigated. Doping with Cr ions gradually increased the metal-insulator transition (MIT) temperature of the films, while the luminous transmittance (Tlum) and the sol modulation efficiency (ΔTsol) gradually decreased. Additionally, Pt/VO2/ITO devices and Cr-doped VO2 devices were prepared to study their threshold switching (TS) properties. For devices fabricated with Cr-doped VO2 films, both the threshold voltage (Vth+) and the OFF-state current decreased as the amount of Cr doping increased. In contrast, the ON/OFF ratio increased from 104 to 105. These results provide insight into the potential for using VO2 in thermochromic, optical, and TS applications.