Abstract As a passive cooling method with no energy input, radiative cooling has great potential in applications like building energy saving. The key to effective radiative cooling lies in selectively controlling the radiative properties in both solar and mid-infrared spectrums, and simple structures based on polymer materials attract growing attentions due to their overwhelming advantages of low cost and large-scalable fabrication. In this study, a dual-layer film consisting of polyvinyl fluoride (PVF) layer and Ag coating is proposed to act as an efficient daytime radiative cooler with low solar absorption and broadband infrared emission. An outdoor test demonstrates that sub-ambient daytime cooling is successfully achieved by the proposed cooler with an equilibrium temperature 2 °C below the ambient under solar irradiation of 950 W/m2. Due to better durability and better performance in anti-staining and corrosion protection than other polymer materials, the demonstrated cooling performance based on the PVF film would facilitate radiative cooling principle in much broader applications.

中文翻译：

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具有宽带红外发射的可伸缩双层薄膜，用于亚环境日间辐射冷却

摘要 辐射冷却作为一种无能量输入的被动冷却方式，在建筑节能等方面具有巨大的应用潜力。有效辐射冷却的关键在于选择性地控制太阳和中红外光谱的辐射特性，基于聚合物材料的简单结构因其低成本和可大规模制造的压倒性优势而受到越来越多的关注。在这项研究中，提出了一种由聚氟乙烯 (PVF) 层和银涂层组成的双层薄膜，作为一种高效的日间辐射冷却器，具有低太阳能吸收和宽带红外发射。一项室外测试表明，在 950 W/m2 的太阳辐射下，平衡温度比环境温度低 2°C 的建议冷却器成功实现了低于环境的白天冷却。