Dual-functional tunable emitter with high visual transparency for energy saving and information encryption

Abstract

Achieving thermal radiation regulation is attractive in the field of thermal management and information security. However, maintaining high visual transparency simultaneously is a challenging task, but it holds vital importance for applications such as smart windows and multispectral information encryption. Here, we designed and fabricated a multilayer film based on thermochromic material vanadium dioxide (VO2) with high transmittance (62.1 %) in visible region and excellent emissivity regulation (0.3) in mid-infrared region. Besides, quantities of energy saving simulations among 85 administrative districts in the United States and China and outdoor tests in Shanghai were done to verify the performance in different climates for the application of energy saving smart window. Furthermore, by taking advantage of its high transmittance in visible band and emissivity tunability in mid-infrared band, VO2-based multilayer film has demonstrated the enormous potential application for information encryption through a proof-of-concept validation. By presenting the novel strategy to achieve independent multispectral regulation, this work offers a solution for multidisciplinary fields including green buildings, adaptive multi-scenes camouflage and other information security.