Radiative cooling is a revolutionary sustainable thermoregulating technology in favor to fight against global warming and urban heat island effects. However, the conventional designed high infrared emissive coolers do not function satisfactorily under atmospheric counter radiation (cloudy, humid, reduced sky access conditions) nor for all‐season thermal requirement (cooling and/or heating). Dual‐mode asymmetric photonic mirror (APM) consisted of silicon‐based diffractive gratings is presented, approaching an all‐season and all‐terrain optimized radiative thermal regulation. Based on the mechanism of asymmetric diffraction through high refractive index contrast mediums, the designed APM establishes an asymmetric radiative heat transfer channel for cooling and heating. An average infrared asymmetry of 20% for outgoing and incoming radiation is achieved by the fabricated APM. The remarkable cooling power of APM surpasses 80% over the standalone radiative cooler (RC) for counter radiation conditions. Under cloudy sky, the cooling‐APM achieves 8 °C lower than RC standalone, while the heating‐APM 5.7 °C higher, which presents prominent advantages over conventional coolers for different thermal management needs. The proposed dual‐mode infrared asymmetric photonic structure is promising to overcome shortcomings of conventional radiative cooling and offers breakthrough developments in future energy‐saving thermal management system.

The overheating/cooling of spacecraft solar cells under the contrastive temperature variation due to solar influence leads to severe consequences on both its performance and its long‐term stability. Radiative thermal management by broadband optical modulating coating provides a versatile and effective solution for spatial environments. Here we design a visible‐to‐mid‐infrared broadband modulating metal oxide‐based electrochromic coating for spacecraft solar cell thermal management. Upon impedance matching between multilayered architecture and control of crystallinity of WO3 with optimized morphology, the final coating successfully presents reversible transition from solar transmitter and thermal emitter to heat preserving coating with infrared (IR) stealth ability. The transmission spectrum of the coating in its bleached state fits the solar spectrum curve (0.3‐1.2 μm) for photocurrent harvesting and it transmits up to 88% at 450 nm, at the solar radiation peak. The average mid‐infrared (MIR) (2‐16 μm) emissivity of the coating is 80%, with a tunability of 20% in average. The demonstrated capabilities of broadband modulating electrochromic coating are highly promising for solar cell thermoregulation in space or terrestrial environments and also for IR‐stealth applications in the defense sector.

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