Optimally Designed Multimaterial Microparticle-Polymer Composite Paints for Passive Daytime Radiative Cooling

Jooyeong Yun, Dongwoo Chae, Sunae So, Hangyu Lim, Jaebum Noh, Junkyeong Park, Namyeong Kim, Cherry Park, Heon Lee, Junsuk Rho

Research output: Contribution to journalArticlepeer-review

25 Citations (Scopus)


Passive daytime radiative cooling (PDRC) devices have enabled subambient cooling of terrestrial objects without any energy input, offering great potential to future clean energy technology. Among various PDRC structures, random dielectric particles in a polymer matrix or paint-like coatings have displayed powerful radiative cooling performances with excellent scalability and easy fabrication. While modeling and analyzing such a system is nontrivial to enhance the cooling effect and engineer the structures to be utilized in various applications, it is essential to understand its complex physical relations and determine the optimal design conditions. In this work, we have thoroughly analyzed the optical properties and radiative cooling performances of PDRC paints composed of two-material particles (SiO2 and Al2O3) using 2D FDTD simulation and investigated the optimal design conditions. Specifically, we have studied the effects of design parameters, such as particle size, size distribution, binder volume ratio, and coating thickness. Subsequently, we have conducted an outdoor cooling measurement of the fabricated PDRC paints to demonstrate their radiative cooling potential and to analyze and understand their performance based on our numerical investigations. The fabricated PDRC paints exhibited high solar reflectance (0.958) and strong long-wave infrared emission (0.937) in the atmospheric transparency window, achieving a maximum temperature drop of 9.1 °C. This comprehensive study provides a detailed characterization of the structure and material parameters of the multimaterial PDRC paint system.

Original languageEnglish
Pages (from-to)2608-2617
Number of pages10
JournalACS Photonics
Issue number8
Publication statusPublished - 2023 Aug 16

Bibliographical note

Funding Information:
This work was financially supported by the POSCO-POSTECH-RIST Convergence Research Center program funded by POSCO, and the National Resto this workearch Foundation (NRF) grants (NRF-2022M3H4A1A02046445, NRF-2018M3D1A1058997, NRF-2019R1A5A8080290, NRF-2022M3C1A3081312) funded by Ministry of Science and ICT (MSIT) of the Korean government. H.L. acknowledges the NRF grants (NRF-2020R1A2C3006382, NRF-2019K1A4A7A02113032) funded by the MSIT and the Technology Innovation Program (20016234, Nano-molding materials with ultrahigh refractive index for meta-lens) funded By the Ministry of Trade, Industry & Energy (MOTIE) of the Korean Government. J.Y. acknowledges the NRF International Research & Development fellowship (NRF-2022K1A3A1A12080092) funded by the MSIT of the Korean Government. D.C. acknowledges the NRF Global Ph.D. fellowship (NRF-2019H1A2A1076622) funded by the Ministry of Education (MOE) of the Korean Government. S.S. acknowledges the NRF Sejong Science fellowship (NRF-2022R1C1C2009430) and the Institute of Information & Communications Technology Planning & Evaluation (IITP) grant (No. 2019-0-01906, the POSTECH Artificial Intelligence Graduate School program) funded by the MSIT of the Korean Government.

Publisher Copyright:
© 2023 American Chemical Society.


  • light scattering
  • metamaterials
  • microspheres
  • nanophotonics
  • optical simulation
  • thermal emission

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biotechnology
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Optimally Designed Multimaterial Microparticle-Polymer Composite Paints for Passive Daytime Radiative Cooling'. Together they form a unique fingerprint.

Cite this