Dual-Functional Photonic Metacoating Integrating Fluorescence Thermometry and High-Performance Space Radiative Cooling

Highlights Dual-functional Eu-doped ZrO2 submicrosphere metacoating for space radiative cooling and fluorescence thermometry. Photonic structure and materials co-design yield an ultralow solar absorptance (α s = 0.076) and high emittance (ε = 0.931) in a ~ 100 μm thick metacoating. The metacoating achieves a net cooling power of 323.69 W m−2 and enables 173–433 K non-contact thermometry (S r,max = 0.797% K−1) with reliable irradiation resistance under space environments.