TY - JOUR
T1 - Simultaneously enhanced solar absorption and radiative cooling with thin silica micro-grating coatings for silicon solar cells
AU - Long, Linshuang
AU - Yang, Yue
AU - Wang, Liping
N1 - Funding Information:
We would like to thank the support from the National Science Foundation (NSF) under Grant No. CBET-1454698 . Access to the NanoFab at Arizona State University for sample fabrication was supported in part by NSF contract ECCS-1542160 .
Funding Information:
We would like to thank the support from the National Science Foundation (NSF) under Grant No. CBET-1454698. Access to the NanoFab at Arizona State University for sample fabrication was supported in part by NSF contract ECCS-1542160.
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/8/1
Y1 - 2019/8/1
N2 - Recently, the idea of radiative cooling by dissipating infrared thermal energy to the cold space through the atmospheric window, especially from 8 to 13 μm in wavelength, has become an attractive way to cool down outdoor devices. Here we show that thin silica (SiO 2 ) micro-gratings as solar-transparent and radiatively cooling coatings for silicon solar cells. The well-designed silica micro-gratings were fabricated with plasma-enhanced chemical vapor deposition, photolithography, and reactive ion etching processes. Spectrometric measurements showed that the SiO 2 micro-gratings atop doped silicon wafer could remarkably enhance the infrared emittance up to 100% within the atmospheric window and increase the solar absorptance with anti-reflection. Numerical modeling confirmed the measured optical and radiative properties and elucidated the underlying physical mechanisms for the anti-reflection in the solar spectrum and enhanced infrared thermal emission. The radiative cooling performance calculated based on a heat transfer model signified that by enhancing the radiative heat dissipation to the space, the grating structure could increase the radiative cooling power when the structure temperature is higher than 45 °C, and reduce the stagnation temperature by up to 20 °C depending on convective heat transfer coefficients. Furthermore, an outdoor field test has been conducted to experimentally demonstrate the cooling performance of the silica micro-gratings, where the grating covered sample showed a lower temperature than the bare silicon sample did under direct sunlight.
AB - Recently, the idea of radiative cooling by dissipating infrared thermal energy to the cold space through the atmospheric window, especially from 8 to 13 μm in wavelength, has become an attractive way to cool down outdoor devices. Here we show that thin silica (SiO 2 ) micro-gratings as solar-transparent and radiatively cooling coatings for silicon solar cells. The well-designed silica micro-gratings were fabricated with plasma-enhanced chemical vapor deposition, photolithography, and reactive ion etching processes. Spectrometric measurements showed that the SiO 2 micro-gratings atop doped silicon wafer could remarkably enhance the infrared emittance up to 100% within the atmospheric window and increase the solar absorptance with anti-reflection. Numerical modeling confirmed the measured optical and radiative properties and elucidated the underlying physical mechanisms for the anti-reflection in the solar spectrum and enhanced infrared thermal emission. The radiative cooling performance calculated based on a heat transfer model signified that by enhancing the radiative heat dissipation to the space, the grating structure could increase the radiative cooling power when the structure temperature is higher than 45 °C, and reduce the stagnation temperature by up to 20 °C depending on convective heat transfer coefficients. Furthermore, an outdoor field test has been conducted to experimentally demonstrate the cooling performance of the silica micro-gratings, where the grating covered sample showed a lower temperature than the bare silicon sample did under direct sunlight.
KW - Micro-grating coating
KW - Radiative cooling
KW - Silicon solar cells
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U2 - 10.1016/j.solmat.2019.04.006
DO - 10.1016/j.solmat.2019.04.006
M3 - Article
AN - SCOPUS:85064080155
SN - 0927-0248
VL - 197
SP - 19
EP - 24
JO - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
ER -