Passive Radiative Cooling Employing Vanadium Dioxide-based Metasurface

Passive radiative cooling (PRC) involves spontaneous heat emission by an object as a thermal radiation into the outer space [1] – an innovative and environmentally sustainable energy-efficient cooling technology that reduces the electrical energy consumption for cooling purposes. PRC is now in the global research limelight and various R&D approaches pivoted to PRC has been reported in the literature [2]. In the context of radiative heat transfer [6]. At low temperatures (i.e., < 68°C), VO 2 exhibits high emissivity within the atmospheric window (8–13 µm), whereas at elevated temperatures (i.e., > 68°C), it has low emissivity but high reflectance in the solar spectrum. The potential of VO 2 in passive radiative cooling needs to be further explored for effective and practical industrial use.