AI 中文总结
本文提出一种无需光刻的被动式日间彩色辐射冷却器，通过DBR与MgF2间隔层实现CMY色彩生成，PDMS层提供强热发射，日间可降温约12℃，适用于多种户外节能热管理场景。
AI 中文摘要
被动式日间彩色辐射冷却（PDCRC）为热管理提供了一种兼具结构着色的诱人方案，但同时实现强日间冷却效果与鲜艳、稳定的色彩仍具挑战性。本文提出一种无需光刻的PDCRC，包含聚二甲基硅氧烷（PDMS）发射体、SiC/SiO2分布式布拉格反射镜（DBR）、MgF2间隔层及Ag背反射镜。DBR与MgF2间隔层可选择性反射可见光以生成青、品红、黄（CMY）色彩，而PDMS层则在大气透明窗口（8-14微米）内提供强热发射。经传输矩阵法（TMM）验证的时域有限差分（FDTD）模拟显示，该冷却器在大气窗口内的平均发射率达92%，在0.75-6微米波段的平均反射率达93.3%。CIE 1931色度分析证实其生成的CMY色彩对比度高，与标准减色三原色的色差低。在日间条件（传热系数为6 W m-2 K-1）下，该冷却器的冷却功率约为140-145 W m-2，温度较环境降低约12摄氏度。色彩特性在宽入射角范围内保持稳定，仅在大角度时色彩强度逐渐降低，光谱响应对TE、TM偏振几乎不敏感。基于全球不同城市气象条件的模拟进一步表明，该冷却器在多样环境下均具备稳定的冷却性能。兼具高冷却性能、鲜艳色彩、简单多层结构及制造可行性，所提出的PDCRC有望应用于建筑、车辆涂层、可穿戴设备及其他户外场景的节能热管理。
英文摘要
Passive daytime colored radiative cooling (PDCRC) offers an attractive approach to thermal management while enabling structural coloration. However, achieving both strong daytime cooling and vivid, stable colors remains challenging. Here, we propose a lithography-free PDCRC comprising a polydimethylsiloxane (PDMS) emitter, SiC/SiO2 distributed Bragg reflector (DBR), MgF2 spacer, and Ag back reflector. The DBR and MgF2 spacer enable selective visible-spectrum reflection for cyan, magenta, and yellow (CMY) color generation, while the PDMS layer provides strong thermal emission within the atmospheric transparency window (8-14 micrometers). Finite-difference time-domain (FDTD) simulations, validated using the transfer matrix method (TMM), yield an average emissivity of 92% in the atmospheric window and an average reflectivity of 93.3% over 0.75-6 micrometers. CIE 1931 chromaticity analysis confirms high-contrast CMY colors with low color differences from standard subtractive primary colors. Under daytime conditions with a heat-transfer coefficient of 6 W m-2 K-1, the proposed cooler achieves cooling powers of approximately 140-145 W m-2 and a temperature reduction of about 12 degrees C below ambient. The color characteristics remain stable over a broad range of incidence angles, with only a gradual reduction in color intensity at larger angles, while the spectral response remains nearly insensitive to TE and TM polarizations. Simulations using meteorological conditions from different global cities further demonstrate robust cooling performance under diverse environmental conditions. The combination of high cooling performance, vivid coloration, simple multilayer architecture, and fabrication feasibility makes the proposed PDCRC promising for energy-efficient thermal management in buildings, vehicle coatings, wearable devices, and other outdoor applications.
Comments20 pages, 8 figures, 2 tables
