Striped VO₂ metasurfaces: Overcoming the solar absorption–infrared emission trade-off for temperature-adaptive radiative cooling

Temperature-adaptive radiative cooling devices (TARDs) automatically adjust their infrared emissivity in response to temperature changes, holding great application potential for building energy conservation, electronic thermal management, and space thermal control. However, TARDs constructed with VO₂ Fabry–Pérot resonant structures face an inherent trade-off between high infrared emissivity and low solar absorptance. In this work, we designed a one-dimensional VO₂ grating metasurface-enhanced temperature-adaptive radiative cooling device (MTARD) with an VO₂/HfO₂/Ag multilayer stack to alleviate this trade-off. Three strip-structured MTARD samples, denoted P4-L2, P6-L3, and P8-L4, were fabricated via facile lithography and magnetron sputtering processes guided by finite-difference time-domain (FDTD) simulations. The P6-L3 configuration achieves optimal thermo-optical performance, featuring a high-temperature emissivity ( ε _H) of 0.83 and an emissivity tunability (Δ ε ) of 0.50, both higher than 0.75 and 0.42 for the planar TARD. Its high-temperature solar absorptance ( α _sol) is also reduced from 49.45% to 36.41%. FDTD simulation results reveal that the striped VO₂ metasurface boosts infrared light absorption through surface plasmon polariton resonances and localized electromagnetic polariton resonances. This work presents a straightforward metasurface architecture that simultaneously reduces solar absorption and elevates infrared emissivity, expanding the conceptual framework and practical fabrication pathways for low-cost high efficient tunable-emissivity devices.