Thermochromic Fenestration Based on VO_2: Finally a Technology of Practical Interest?

摘要

Vanadium-dioxide-based thermochromic thin films and nanoparticle composites can have significant transmittance for visible light, T_(lum), while at the same time they are able to transmit more near-infrared solar radiation at τ < τ_c than at τ > τ_e, where τ denotes temperature and τ_c the critical temperature, τ_c ≈ 68°C. It has been understood for many years that these properties are of principle interest for energy-efficient fenestration, but the technology has been slow to mature. The present paper summarizes the state of the art of VO_2-based thermochromics and points at the many advances that have been made during recent years. Specifically, the paper discusses how to employ doping to adjust τ_c to room temperature and to increase T_(lum), how to use nano-materials to enhance the solar energy transmittance modulation and T_(lum), and how to prepare nanoparticle composites by sputtering. A brief discussion is given on thermochromic light scattering, which is a recently discovered phenomenon.