Author
Kecebas, M. A., Mengüç, Mustafa Pınar, Kosar, A., Sendur, K.
Publication Date
2017-09
Publication Place
-
Elsevier
Subject
Passive radiative cooling, Thermal radiation, Broadband optical filters, Selective absorption and emission, Two-dimensional thin film coatings
Type
Periodical
Language
English
Digital
Yes
Manuscript
No
Library
Özyeğin University
Library Asset ID
1879-1352
Record ID
6ef3b22a-76e2-4bac-bab8-16c821270500
Library Location
Mechanical Engineering
Date
2017-09
Sample Text
The operation of most electronic semiconductor devices suffers from the self-generated heat. In the case of photovoltaic or thermos-photovoltaic cells, their exposure to sun or high temperature sources make them get warm beyond the desired operating conditions. In both incidences, the solution strategy requires effective radiative cooling process, i.e., by selective absorption and emission in predetermined spectral windows. In this study, we outline two approaches for alternative 2D thin film coatings, which can enhance the passive thermal management for application to electronic equipment. Most traditional techniques use a metallic (silver) layer because of their high reflectivity, although they display strong absorption in the visible and near-infrared spectrums. We show that strong absorption in the visible and near-infrared spectrums due to a metallic layer can be avoided by repetitive high index-low index periodic layers and broadband reflection in visible and near-infrared spectrums can still be achieved. These modifications increase the average reflectance in the visible and near-infrared spectrums by 3–4%, which increases the cooling power by at least 35 W/m2. We also show that the performance of radiative cooling can be enhanced by inserting an Al2O3 film (which has strong absorption in the 8–13 µm spectrum, and does not absorb in the visible and near-infrared) within conventional coating structures. These two approaches enhance the cooling power of passive radiative cooling systems from the typical reported values of 40 W/m2–100 W/m2 and 65 W/m2 levels respectively.
DOI
10.1016/j.jqsrt.2017.03.046
Cilt
198
