Photonic design for color compatible radiative cooling accelerated by materials informatics

Abstract

Passive radiative cooling can dissipate heat load directly through the high transparency atmospheric window (8–13 μm). The conventional strategy for radiative cooling has mainly focused on simultaneously blocking the total solar heating and enhancing the infrared emission, which makes the appearance either specular or diffusive white. Recently proposed colored radiative coolers can realize the colored radiative cooling but with limited color gamut. In this work, we have designed both transmissive and reflective colored radiative coolers that realize radiative cooling with ultra-wide color gamut. The optimal structures are identified with Bayesian optimization by only evaluating less than 1% of the candidate structures, which dramatically accelerates the design process. The optimized transmissive colored radiative cooler can produce standard additive colors and realize sub-ambient cooling effect at moderate environment conditions. The reflective colored radiative cooler is highly transparent in visible light range and can largely reduce the thermal load as well as enhance heat dissipation by radiative heat transfer.