Sub-ambient daytime radiative cooling by silica-coated porous anodic aluminum oxide

Dasol Lee, Myeongcheol Go, Soomin Son, Minkyung Kim, Trevon Badloe, Heon Lee, Jin Kon Kim, Junsuk Rho

Research output: Contribution to journalArticlepeer-review

121 Citations (Scopus)

Abstract

An energy-free daytime radiative cooler based on silica-coated porous anodic aluminum oxide is proposed, optimized, and experimentally realized. It is shown that a simple thin silica layer coating on porous anodic aluminum oxide can produce the spectral emissivity in the atmospheric window (8-13μm) required for sub-ambient cooling effect under direct sunlight. The final design, optimized using effective medium theory, exhibits high reflectance of 0.86 in the solar spectral region, and a substantial average emissivity of 0.96 in the atmospheric window. The fabricated centimeter-scale radiative cooler demonstrates a maximum cooling of 6.1 °C below ambient during the daytime. We believe that the proposed approach is a promising way to produce inexpensive and efficient radiative coolers.

Original languageEnglish
Article number105426
JournalNano Energy
Volume79
DOIs
Publication statusPublished - 2021 Jan

Bibliographical note

Funding Information:
Prof. Jin Kon Kim is a POSTECH fellow and a full professor in Chemical Engineering at POSTECH. Also, he is the director of the Center for Smart Block Copolymer Self-Assembly funded by the National Creativity Research Initiative Program supported by National Research Foundation of Korea. He received his B.S. (1980) from Seoul National University (Korea) in Chemical Engineering and M.S. (1982) from Korea Advanced Institute of Science and Technology (Korea) in Chemical Engineering, and Ph.D. (1990) from Polytechnic University in Chemical Engineering. His research interests include phase behavior and transition of block copolymers, development of new functional nanocomposites containing polymer blends.

Funding Information:
This work was supported by the Green Science program funded by POSCO and the National Research Foundation (NRF) grants ( NRF-2019R1A2C3003129 , CAMM-2019M3A6B3030637 , NRF-2019R1A5A8080290 , NRF-2018M3D1A1058997 ) funded by the Ministry of Science and ICT (MSIT) , Republic of Korea. J.K.K. acknowledges the National Creative Research Initiative program ( NRF-2013R1A3A2042196 ) funded by the NRF-MSIT, Republic of Korea . M.K. acknowledges the NRF Global PhD fellowship ( NRF - 2017H1A2A1043204 ) funded by the Ministry of Education, Republic of Korea .

Funding Information:
This work was supported by the Green Science program funded by POSCO and the National Research Foundation (NRF) grants (NRF-2019R1A2C3003129, CAMM-2019M3A6B3030637, NRF-2019R1A5A8080290, NRF-2018M3D1A1058997) funded by the Ministry of Science and ICT (MSIT), Republic of Korea. J.K.K. acknowledges the National Creative Research Initiative program (NRF-2013R1A3A2042196) funded by the NRF-MSIT, Republic of Korea. M.K. acknowledges the NRF Global PhD fellowship (NRF-2017H1A2A1043204) funded by the Ministry of Education, Republic of Korea.

Publisher Copyright:
© 2020

Keywords

  • Anodic aluminum oxide
  • Atomic layer deposition
  • Daytime
  • Passive
  • Radiative cooling
  • Selective emitter

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • General Materials Science
  • Electrical and Electronic Engineering

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