Polarization-mediated multi-state infrared system for fine temperature regulation

Passive radiative cooling has been spotlighted as a promising energy-saving technology owing to its energy-free and zero-carbon emission for addressing global energy climate crises. Although can significantly save in hot weather, it inevitably accompanies undesirable cold weather resulting from single-state of strong thermal emission. Dual-state emitters have recently developed self-adaptive thermoregulation, but they still exhibit loss moderate weather. Herein, we report “continuous” temperature-regulation system by introducing an infrared (IR) polarization valve the energy-balancing channel. The proposed scheme controls emitter temperature simply in-plane rotation IR polarizer if closing opening valve, which presents heating/cooling capabilities −17 51 W/m2 >20 GJ/year compared with conventional all zones. Outdoor experiments demonstrate precise regulation range ΔTcool >2 °C. This proof-of-concept demonstration outdoors verifies our approach’s reliability, suggesting applicability residential buildings, farms, electronic devices.