Thermochromic VO2 for Energy-Efficient Smart Windows

Rapid development of the thermochromic glazing technique promisesnext-generation architectural windows with energy-saving characteristics by intelligently regulating indoor solar irradiation via modulating their optical properties in response to the surrounding temperature.Vanadium dioxide (VO2) is a promising material for energy-saving smart windows due to its reversible metal-to-insulator transition near room temperature, accompanying with large changes in its optical properties.This review provides a comprehensive overview of the application of VO2 to smart windows with particular emphasis on recent progress from the electronic-, atomic-, nano-and micron-perspectives.The effects of intrinsic atomic defects, elemental doping, and lattice strain on VO2 nanocrystals are examined.Nano-and microscale morphology engineering approaches are summarized aiming to enhance the thermochromic performance and impart practical multi-functionalities.Finally, the challenges and future directions of VO2-based smart windows are elaborated to bridge the gap between the lab research and large scale practical applications.