Passive Radiative Cooling Materials and Their Applications

Abstract

Passive radiative cooling naturally lowers the temperature of a cooler by reflecting sunlight and emitting heat into the frigid expanse of universe. While certain natural and synthetic substances may exhibit distinct radiative properties, their radiative efficiency remains minimal. As a result of the notable advancements in micro-nano technology, scientists have created several novel substances that exhibit minimal absorption within the intense solar spectrum (0.3-2.5 μm) but possess elevated emissivity in alternative wavelengths, ideally falling in the atmospheric window spectrum (8-13 μm). The basics of radiative cooling mechanisms are presented in this review, along with an overview of the progress made in radiative materials and their various applications. In upcoming times, this technology of passive radiative cooling, which consumes no energy and produces no greenhouse gases, will become a prominent approach for cooling purposes.