Designing photonic structures for high performance radiative cooling using genetic algorithm

Abstract

Recent progresses on passive radiative cooling methods have achieved cooling to a temperature below ambient surface [1, 2]. Here, we propose one-dimensional photonic crystals for high performance radiative cooling [3]. For high performance radiative cooling, high solar reflectance at solar region is essential as well as strong thermal emission in the atmospheric window between 8 and 13 micrometers. We demonstrate simultaneous structural optimization of one-dimensional photonic crystals for both wavelength region of solar and mid-IR. For photonic structural design, an evolutionary optimization of genetic algorithm is used to optimize both types of materials and structure parameters of the multilayer structures. The designed photonic structures strongly reflect light at solar region while strongly emit light in the atmospheric window. The designed photonic structures show very high radiative cooling performance because it is optimized in both regions at the same time. We believe the research finding will provide a possibility to solve energy problems.