Structure optimization of metallodielectric multilayer for high-efficiency daytime radiative cooling

Takahiro Suichi, Atsushi Ishikawa, Yasuhiko Hayashi, Kenji Tsuruta

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


Engineered metallodielectric nanostructures offer a new platform for controlling thermal emission in a desired manner, thus promise potential applications in passive cooling devices. Here, we present optimization design of metallodielectric multilayer structures for high-efficiency daytime radiative cooling and experimentally characterize their cooling performance. The device structure consists of alternating layers of SiO2 and PMMA on an Ag mirror, which works as a selective thermal emitter at 8-13 μm with a high reflectance for sunlight. Automated design scheme based on simulated annealing method combined with photonic-thermal analysis is developed and applied to search the optimized number and thickness of the layers. The evaluation function in the optimization process is predefined such that a net emission power would be maximized at the ambient temperature of 27 °C (300 K) under the sunlight irradiation of AM1.5G. The numerical results prove efficient radiative cooling to 3.0 °C lower than the ambient temperature, corresponding to 6.6 °C below the bare Ag mirror temperature. Based on the optimized design, the device is fabricated on an Al mirror by using reactive evaporation and spin-coating process over an area of 25 × 25 mm2. The reflectance and absorption properties of the fabricated device are characterized to demonstrate the selective thermal radiation through an atmospheric window. The equilibrium temperature of the device is also investigated to demonstrate the cooling performance under the direct sunlight irradiation.

Original languageEnglish
Title of host publicationThermal Radiation Management for Energy Applications
EditorsPeter Bermel, Mowafak M. Al-Jassim
ISBN (Electronic)9781510611955
Publication statusPublished - 2017
EventThermal Radiation Management for Energy Applications 2017 - San Diego, United States
Duration: Aug 9 2017Aug 10 2017

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherThermal Radiation Management for Energy Applications 2017
Country/TerritoryUnited States
CitySan Diego


  • Computer-Aided Automated Design
  • Daytime Radiative Cooling
  • Metallodielectric Multilayer
  • Simulated Annealing Method

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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