Designing Plasmon‐Enhanced Thermochromic Films Using a Vanadium Dioxide Nanoparticle Elastomeric Composite

Vanadium dioxide (VO₂) is a common material for use in thermochromic windows due to a semiconductor‐to‐metal transition (SMT) that is coupled with a change in infrared opacity. Commercialization of VO₂‐based thermochromic technology is hampered by relatively expensive synthesis and film fabrication techniques as well as overall low performance as a window material. Here, simulations that indicate the plasmon resonance of VO₂ nanoparticles in a composite film, which can be tuned to achieve record performance values, are reported. These simulations are experimentally verified by fabricating a VO₂ nanoparticle composite in an elastomeric matrix using low‐temperature and atmospheric processing conditions. The optical properties of the films are analyzed, yielding visible transmittance and infrared modulation values within the range of top‐performing thermochromic windows. In addition, an improvement in performance is observed upon stretching the films, an effect that can be attributed to a local refractive index modulation. The results highlight the potential use of elastomeric composites as a low‐cost route to higher‐performance smart windows.