Multifunctional Daytime Radiative Cooling Devices with Simultaneous Light-Emitting and Radiative Cooling Functional Layers.

In this study, multifunctional light-emitting and passive radiative cooling (LEPC) materials and devices are designed by embedding chemically designed perovskite nanocrystals (NCs) into the radiative polymer layer. Lead halide perovskite NCs are chosen as the light-emitting material, owing to their high photon radiation rate and low phonon generation. To integrate the perovskite NCs into the radiative polymer layers, a surface passivation is achieved by coating the NCs with silica. The silica shell synergistically improves the chemical stability and cooling efficiency. Both outdoor experimental and simulation results demonstrate that the fabricated LEPC devices show better cooling performance than conventional cooling devices. The LEPC devices are easily patterned by utilizing pixelating, assembling, and simple cutting or drawing techniques with the LEPC materials. This study also demonstrates the potential applications of these materials as components of smart building systems, in smart window displays, or for anticounterfeiting cooling systems, thus proving the practicality of these multifunctional LEPC devices.