Photoluminescent Dual-Layer Electrospinning Films for Colored Passive Radiative Cooling

Abstract With the increasing demand for energy-efficient cooling technologies, passive daytime radiative cooling (PDRC) has emerged as a promising strategy for achieving subambient cooling without energy input. However, conventional PDRC materials typically rely on highly reflective white surfaces, limiting their applicability in scenarios requiring aesthetic diversity. A photoluminescent dual-layer colored radiative cooling composite film (CRC) is developed via continuous electrospinning technology. The film consists of a bottom reflective layer composed of PVDF-HFP nanofibers doped with SiO2/Al2O3 particles to enhance solar scattering, and a top photoluminescent layer incorporating fluorescent dyes for color generation. This dual-layer configuration enables the introduction of color while largely preserving high solar reflectance and mid-infrared emissivity. To accurately evaluate the optical performance of photoluminescent systems, a combined colorimetric–spectral characterization method (CS) is employed to decouple fluorescence-induced pseudoreflectance in the visible region. The resulting films exhibit a solar reflectance of ∼88% and an emissivity exceeding 97% within the atmospheric window (8–13 μm). These optical properties enable effective cooling performance: outdoor measurements demonstrate a daytime subambient cooling of up to 3.8–5.2 °C under direct sunlight, along …