Analysis of radiative cooling effect and Bragg reflector

Radiative cooling structures can reach a temperature below the ambient temperature by reducing the absorption of radiative energy from the surrounding environment, while maximizing the radiative energy emission. These structures have received extensive attention given their potential to reduce buildings’ electrical power consumption. To achieve this goal, a structure with specific electromagnetic properties regarding wave absorption and transmission should be designed. The proposed structure should simultaneously have 1) good reflectance across the Sun radiation spectrum, and 2) good emittance (absorptance) in the atmospheric window wavelength range. In this article, the SU-8 photoresist material was proposed to fulfill the emission condition, and to fulfill the reflection condition, the Bragg reflector was considered and analyzed.