A dual-selective thermal emitter with enhanced subambient radiative cooling performance

Radiative cooling is a zero-energy technology that enables subambient cooling by emitting heat into outer space (similar to 3 K) through the atmospheric transparent windows. However, existing designs typically focus only on the main atmospheric transparent window (8-13 mu m) and ignore another window (16-25 mu m), under-exploiting their cooling potential. Here, we show a dual-selective radiative cooling design based on a scalable thermal emitter, which exhibits selective emission in both atmospheric transparent windows and reflection in the remaining mid-infrared and solar wavebands. As a result, the dual-selective thermal emitter exhibits an ultrahigh subambient cooling capacity (similar to 9 degrees C) under strong sunlight, surpassing existing typical thermal emitters (>= 3 degrees C cooler) and commercial counterparts (as building materials). Furthermore, the dual-selective sample also exhibits high weather resistance and color compatibility, indicating a high practicality. This work provides a scalable and practical radiative cooling design for sustainable thermal management.