Pyramid Textured Photonic Films with High‐Refractive Index Fillers for Efficient Radiative Cooling

Sub-ambient cooling technologies relying on passive radiation have garnered escalating research attention owing to the challenges posed by global warming and substantial energy consumption inherent in active cooling systems. However, achieving highly efficient radiative cooling devices capable of effective heat dissipation remains a challenge. Herein, by synergic optimization of the micro-pyramid surface structures and 2D hexagonal boron nitride nanoplates (h-BNNs) scattering fillers, pyramid textured photonic films with remarkable solar reflectivity of 98.5% and a mid-infrared (MIR) emittance of 97.2% are presented. The h-BNNs scattering filler with high thermal conductivity contributed to the enhanced through-plane thermal conductivity up to 0.496 W m