Zhong Lin Wang, Georgia Institute of Technology, Atlanta, USA, and co-workers, Chinese Academy of Sciences, Beijing, created a three-layered TiO₂/VO₂/FTO/substrate structure that responds to its environmental temperature, making it a promising material for energy efficient windows.

While still allowing visible light to get through, VO₂ can change from a transparent semiconductive state at low temperatures, allowing infrared radiation through, to an opaque metallic state at high temperatures, reflecting infrared readiation. The FTO layer enhances the crystallinity of the VO₂ film which is important for improving the material’s performance and reducing its cost.

• Solution-based fabrication of vanadium dioxide on F:SnO₂ substrates with largely enhanced thermochromism and low-emissivity for energy-saving applications,
  Zongtao Zhang, Yanfeng Gao, Hongjie Luo, Litao Kang, Zhang Chen, Jing Du, Minoru Kanehira, Yuzhi Zhang, Zhong Lin Wang,
  Energy Environ. Sci. 2011.
  DOI: 10.1039/c1ee02092g