Enhanced electrical and optical properties of porous W-doped V2O5 films under thermally and electrically induced phase transition

Abstract

Herein, the nanoscale porous W-doped V2O5 thin film was prepared by sol–gel method and post-annealing process on fluorine-doped SnO2 (FTO) conductive glass substrate using polyethylene glycol (PEG) as the structure guide agent. Then a metal–semiconductor-metal (MSM) structure device was fabricated based on the prepared film. The analysis of the surface morphology, elemental constituents, and photoelectric properties confirms the successful formation of a porous W-doped V2O5 film, which exhibited improved electrical and optical properties. Under thermally and electrically induced phase transition, the maximum transmittance modulation depth of the film reached 17.74% at 700 nm between 20 °C and 320 °C and 36.46% at 600 nm under 0.5 V bias voltage, respectively. In the range of 700–1500 nm, the average value of the maximum transmittance modulation depth of the film also increased from 2.74% to 16.9% compared with V2O5 film. With repeated temperature cycling, the film was able to maintain good electrical and optical properties, which is expected to be applied to novel integrated optoelectronic and electrochromic devices.