A Multilayer-Based Visibly Transparent Radiative Cooler with Enhanced Solar Selectivity

Abstract

Transparent radiative cooling enables passive thermal management by selectively reflecting solar radiation and emitting thermal energy, thereby offering a promising solution for energy-efficient cooling in transparent applications. Despite recent progress in the development of transparent radiative coolers, achieving a balance between high visible transparency and effective solar reflection remains a critical challenge in enhancing the cooling performance. In this study, a transparent radiative cooler comprising a 50 mu m-thick polydimethylsiloxane (PDMS) emitter integrated with a sophisticated metal-dielectric multilayer is evaluated both experimentally and theoretically. The theoretical simulations demonstrate a visible transmittance >82% and a near-infrared reflectance >92%, with a sharp transition between spectral regimes. Experimental characterizations confirm a visible transmittance of 48% alongside an enhanced near-infrared reflectance of 98%, thereby validating robust cooling performance under real-world conditions. Additionally, daytime outdoor measurements indicate that the cooler achieves a maximum temperature reduction of 10.8 degrees C compared to conventional PDMS-coated glass. Furthermore, global simulations illustrate the cooling effect of this cooler under diverse climatic conditions, highlighting its potential for use in various terrestrial areas.