TY - JOUR
T1 - Spectrally-selective vanadium dioxide based tunable metafilm emitter for dynamic radiative cooling
AU - Taylor, Sydney
AU - Long, Linshuang
AU - McBurney, Ryan
AU - Sabbaghi, Payam
AU - Chao, Jeremy
AU - Wang, Liping
N1 - Funding Information:
This work was supported by a NASA Space Technology Research Fellowship (NNX16AM63H). We would also like to thank support from the National Science Foundation (NSF) under Grant No. CBET-1454698. We are grateful for support from the ASU Fulton Undergraduate Research Initiative program. We would also like to thank the ASU NanoFab and Eyring Center for use of their nanofabrication and characterization facilities supported in part by NSF contract ECCS-1542160.
Funding Information:
This work was supported by a NASA Space Technology Research Fellowship ( NNX16AM63H ). We would also like to thank support from the National Science Foundation (NSF) under Grant No. CBET-1454698 . We are grateful for support from the ASU Fulton Undergraduate Research Initiative program. We would also like to thank the ASU NanoFab and Eyring Center for use of their nanofabrication and characterization facilities supported in part by NSF contract ECCS-1542160 .
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/11
Y1 - 2020/11
N2 - Dynamic radiative cooling with variable emissive power is experimentally demonstrated in this study by a wavelength-selective tunable metafilm emitter, which consists of an opaque aluminum film, a sputtered silicon spacer, and a thermochromic vanadium dioxide (VO2) layer fabricated by a furnace oxidation method. The temperature-dependent spectral emittance, experimentally obtained from spectral reflectance measurements, clearly shows a pronounced emission peak around 10 μm wavelength when the VO2 experiences an insulator-to-metal phase transition near 65 °C. The tunable metafilm emitter achieves a significant total emittance increase from 0.14 at room temperature to 0.60 at 100 °C. Theoretical modeling based on thin-film optics indicates that the emission enhancement at high temperatures is realized by Fabry-Perot cavity resonance with the metallic VO2 film. Moreover, a calorimetry-based thermal vacuum experiment was conducted and the enhanced thermal emission of the fabricated tunable metafilm sample was experimentally demonstrated at temperatures higher than the phase transition temperature, compared to black, aluminum and doped silicon samples, whose emittance changes little near room temperatures. The developed tunable metafilm emitter with variable spectrally-selective emittance in the mid-infrared holds great promise for both terrestrial and extraterrestrial dynamic radiative cooling applications.
AB - Dynamic radiative cooling with variable emissive power is experimentally demonstrated in this study by a wavelength-selective tunable metafilm emitter, which consists of an opaque aluminum film, a sputtered silicon spacer, and a thermochromic vanadium dioxide (VO2) layer fabricated by a furnace oxidation method. The temperature-dependent spectral emittance, experimentally obtained from spectral reflectance measurements, clearly shows a pronounced emission peak around 10 μm wavelength when the VO2 experiences an insulator-to-metal phase transition near 65 °C. The tunable metafilm emitter achieves a significant total emittance increase from 0.14 at room temperature to 0.60 at 100 °C. Theoretical modeling based on thin-film optics indicates that the emission enhancement at high temperatures is realized by Fabry-Perot cavity resonance with the metallic VO2 film. Moreover, a calorimetry-based thermal vacuum experiment was conducted and the enhanced thermal emission of the fabricated tunable metafilm sample was experimentally demonstrated at temperatures higher than the phase transition temperature, compared to black, aluminum and doped silicon samples, whose emittance changes little near room temperatures. The developed tunable metafilm emitter with variable spectrally-selective emittance in the mid-infrared holds great promise for both terrestrial and extraterrestrial dynamic radiative cooling applications.
KW - Metafilm
KW - Radiative cooling
KW - Vanadium dioxide
KW - Variable emittance
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U2 - 10.1016/j.solmat.2020.110739
DO - 10.1016/j.solmat.2020.110739
M3 - Article
AN - SCOPUS:85089750741
SN - 0927-0248
VL - 217
JO - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
M1 - 110739
ER -