Adaptive thermally tunable radiative cooling with angle insensitivity using phase-change-material-based metasurface

Radiative cooling is the passive cooling of a material with the help of a specific spectral response to emit thermal energy into space through atmospheric transparency windows. However, most of the proposed designs have no dynamically tunable emission response. In this paper, we present a feasible inverse pyramid structure made of a phase change material (PCM) on top of a metallic mirror to realize an adaptive radiative cooler with almost angle-independent emission response. The design uses the thermally controlled PCM called Samarium nickelate (SmNiO3) to actively tune the spectral response of the design, which, in turn, allows the design to radiatively cool itself. The emission response of the design is compatible with atmospheric transmissive windows. As the design heated up to higher temperatures, the peak of the emission spectrum red-shifts and moves toward the atmospheric transparency window.