Angularly selective thermal emitters for deep subfreezing daytime radiative cooling
We theoretically analyze the impact of angular selectivity on the radiative cooling performance of thermal emitters. We investigate the effect of spectral selectivity, environmental conditions, and parasitic heating on the minimum possible equilibrium temperature of the thermal emitter. We show that...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
De Gruyter
2022-08-01
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| Series: | Nanophotonics |
| Subjects: | |
| Online Access: | https://doi.org/10.1515/nanoph-2022-0032 |
| _version_ | 1797947909587599360 |
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| author | Chamoli Sandeep Kumar Li Wei Guo Chunlei ElKabbash Mohamed |
| author_facet | Chamoli Sandeep Kumar Li Wei Guo Chunlei ElKabbash Mohamed |
| author_sort | Chamoli Sandeep Kumar |
| collection | DOAJ |
| description | We theoretically analyze the impact of angular selectivity on the radiative cooling performance of thermal emitters. We investigate the effect of spectral selectivity, environmental conditions, and parasitic heating on the minimum possible equilibrium temperature of the thermal emitter. We show that combining angular and spectral selectivity is necessary to reach deep subfreezing temperatures. We also show that angularly selective thermal emitters increase the cooling performance in humid environments, however, they require management of nonradiative heat transfer processes. We introduce a general scheme to realize angularly and spectrally selective absorption/emission using a thin film stack consisting of an angle dependent transmission filter overlayed on a selective thermal emitter. The thermal emitter total thickness is ∼16 μm, an order of magnitude less than previously proposed angular selective thermal emitters/absorbers and operates under s- and p-polarized light without using anisotropic layers. Under realistic conditions and reasonable parasitic heating, the proposed emitter can be cooled down to ΔT = −46 °C below ambient temperature. Our work highlights the advantages and drawbacks of angular selective thermal emitters towards practical and efficient radiative cooling devices. |
| first_indexed | 2024-04-10T21:35:08Z |
| format | Article |
| id | doaj.art-a3562a45513246998077f1fe07423d59 |
| institution | Directory Open Access Journal |
| issn | 2192-8614 |
| language | English |
| last_indexed | 2024-04-10T21:35:08Z |
| publishDate | 2022-08-01 |
| publisher | De Gruyter |
| record_format | Article |
| series | Nanophotonics |
| spelling | doaj.art-a3562a45513246998077f1fe07423d592023-01-19T12:47:00ZengDe GruyterNanophotonics2192-86142022-08-0111163709371710.1515/nanoph-2022-0032Angularly selective thermal emitters for deep subfreezing daytime radiative coolingChamoli Sandeep Kumar0Li Wei1Guo Chunlei2ElKabbash Mohamed3GPL Photonics Lab, State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun130033, ChinaGPL Photonics Lab, State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun130033, ChinaThe Institute of Optics, University of Rochester, Rochester, NY14627, USAThe Institute of Optics, University of Rochester, Rochester, NY14627, USAWe theoretically analyze the impact of angular selectivity on the radiative cooling performance of thermal emitters. We investigate the effect of spectral selectivity, environmental conditions, and parasitic heating on the minimum possible equilibrium temperature of the thermal emitter. We show that combining angular and spectral selectivity is necessary to reach deep subfreezing temperatures. We also show that angularly selective thermal emitters increase the cooling performance in humid environments, however, they require management of nonradiative heat transfer processes. We introduce a general scheme to realize angularly and spectrally selective absorption/emission using a thin film stack consisting of an angle dependent transmission filter overlayed on a selective thermal emitter. The thermal emitter total thickness is ∼16 μm, an order of magnitude less than previously proposed angular selective thermal emitters/absorbers and operates under s- and p-polarized light without using anisotropic layers. Under realistic conditions and reasonable parasitic heating, the proposed emitter can be cooled down to ΔT = −46 °C below ambient temperature. Our work highlights the advantages and drawbacks of angular selective thermal emitters towards practical and efficient radiative cooling devices.https://doi.org/10.1515/nanoph-2022-0032angularly selective systemradiative coolingthermal designthin film design |
| spellingShingle | Chamoli Sandeep Kumar Li Wei Guo Chunlei ElKabbash Mohamed Angularly selective thermal emitters for deep subfreezing daytime radiative cooling Nanophotonics angularly selective system radiative cooling thermal design thin film design |
| title | Angularly selective thermal emitters for deep subfreezing daytime radiative cooling |
| title_full | Angularly selective thermal emitters for deep subfreezing daytime radiative cooling |
| title_fullStr | Angularly selective thermal emitters for deep subfreezing daytime radiative cooling |
| title_full_unstemmed | Angularly selective thermal emitters for deep subfreezing daytime radiative cooling |
| title_short | Angularly selective thermal emitters for deep subfreezing daytime radiative cooling |
| title_sort | angularly selective thermal emitters for deep subfreezing daytime radiative cooling |
| topic | angularly selective system radiative cooling thermal design thin film design |
| url | https://doi.org/10.1515/nanoph-2022-0032 |
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