Enhancing visible-light transmittance while reducing phase transition temperature of VO2 by Hf-W co-doping

In order to enhance the visible-light transmittance while reducing the insulator-metal transition (IMT) temperature, Hf-W co-doping is designed for modification of VO2. We grow high-quality HfxWyV1-x-yO2 (HfWVO2) alloy films on c-plane sapphire substrates by pulsed laser deposition, and test structural, electrical, and optical properties of the films by various techniques. The Hf-W co-doped VO2 films exhibit outstanding thermochromic performances with a high luminous transmittance up to 41.1%, a fairly good near-infrared modulation capacity of 13.1%, and a low phase transition temperature of 38.9 degrees C. The enhanced luminous transmittance along with reduced IMT temperature in HfWVO2 is attributed to the co-doping synergetic effect of Hf and W, which effectively improves the optical bandgap and donates extra electrons into the system, respectively, while largely retaining the near-infrared modulation capacity of VO2. Our work provides an effective strategy in tailoring VO2 toward practical smart-coating applications by Hf-W co-doping.

Automated summary

By co-doping Hf and W in VO2, we have successfully modified the material to enhance luminous transmittance and near-infrared modulation capacity, while reducing the phase transition temperature. This strategy provides a promising approach for practical smart-coating applications.