Radiative cooling is a passive cooling technology without any energy consumption, compared to conventional cooling technologies that require power sources and dump waste heat into the surroundings. For decades, many radiative cooling studies have been introduced but its applications are mostly restricted to nighttime use only. Recently, the emergence of photonic technologies to achieves daytime radiative cooling overcome the performance limitations. For example, broadband and selective emissions in mid-IR and high reflectance in the solar spectral range have already been demonstrated. This review article discusses the fundamentals of thermodynamic heat transfer that motivates radiative cooling. Several photonic structures such as multilayer, periodical, random; derived from nature, and associated design procedures were thoroughly discussed. Photonic integration with new functionality significantly enhances the efficiency of radiative cooling technologies such as colored, transparent, and switchable radiative cooling applications has been developed. The commercial applications such as reducing cooling loads in vehicles, increasing the power generation of solar cells, generating electricity, saving water, and personal thermal regulation are also summarized. Lastly, perspectives on radiative cooling and emerging issues with potential solution strategies are discussed.

与需要电源并将废热排放到周围环境的传统冷却技术相比，辐射冷却是一种无任何能源消耗的被动冷却技术。几十年来，已经推出了许多辐射冷却研究，但其应用大多仅限于夜间使用。最近，光子技术的出现实现了白天辐射冷却，克服了性能限制。例如，中红外的宽带和选择性发射以及太阳光谱范围的高反射率已经得到证实。这篇综述文章讨论了促进辐射冷却的热力学传热的基本原理。多层、周期、随机等多种光子结构；源自自然，并对相关的设计程序进行了深入讨论。光子与新功能的集成显着提高了辐射冷却技术的效率，例如已开发出彩色、透明和可切换的辐射冷却应用。还总结了减少车辆冷却负荷、增加太阳能电池发电量、发电、节水和个人热调节等商业应用。最后，讨论了辐射冷却的观点以及潜在解决策略的新问题。