arrow
Return

Angularly selective thermal emitters for deep subfreezing daytime radiative cooling

delete2022-08-05
delete19
delete
OA
AI
S
Sandeep Kumar Chamoli
W
Wei Li *
郭春磊 (Chunlei Guo)
M
Mohamed ElKabbash *
DOI:10.1515/nanoph-2022-0032delete
deleteOriginal
deleteShare
deleteSave
View PDF
Abstract

Abstract

En 中文
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 similar to 16 mu m, 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 Delta T = -46 degrees C below ambient temperature. Our work highlights the advantages and drawbacks of angular selective thermal emitters towards practical and efficient radiative cooling devices.
Keywords:
angularly selective system
radiative cooling
thermal design
thin film design
AI Summary

AI Summary

Key information extracted from the uploaded paper, including a brief overview, abstract, background, key highlights, visual analysis, and future outlook.

Journal

Nanophotonics cover
Nanophotonics
IF:
6.6
Papers:
2.9K
Citations:
1.6W

Organization

U
university of chinese academy of sciences, cas
Scholars:
4.1W
Papers: 3.8W
Citations: 75
C
chinese academy of sciences
Scholars:
55.1W
Papers: 44.5W
Citations: 704