Iridescent radiative coolers: Fundamentals, materials design, and emerging applications

Global warming and energy crisis have intensified the demand for sustainable cooling solutions. Radiative cooling has emerged as a promising passive technology capable of dissipating heat without energy input. However, traditional white radiative cooler (RC) often faces limitations such as aesthetic monotony and potential light pollution. Colored radiative coolers (CRCs) address these challenges by combining visual appeal with impressive radiative cooling performance. This review article categorizes CRCs into three types: pigment-based, structural color-based, and emissive color-based systems, focusing on their principles, design strategies, and applications. Key advancements include bilayer designs that balance coloration and thermal radiation, structural innovations that achieve vibrant hues through diffraction and interference. Additionally, emissive materials convert solar absorption into long-wavelength emissions, ensuring effective heat management. By simultaneously addressing the dual challenges of functionality and aesthetics, CRCs expand the applications of passive cooling technology in architecture, transportation, and electronics, paving the way for energy-efficient and sustainable design. • CRC s integrate aesthetics and cooling, overcoming white RC s ’ visual limitations. • Classified CRC s into pigment-, structural-, and emissive color-based systems. • Bilayer and structural designs enable vibrant color with strong cooling ability. • CRC s enable sustainable cooling in buildings, transport, electronics and textiles.