Radiative cooling of solar cells

Zhu, Linxiao; Raman, Aaswath; Wang, Ken Xingze; Anoma, Marc Abou; Fan, Shanhui

doi:10.1364/optica.1.000032

Cited by 456 publications

(271 citation statements)

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“…Moreover, to achieve the cooling of the solar cell layer beneath such encapsulation layers, efficient heat conduction between the top of the encapsulation layers and the solar cell layer will be essential. Previous simulations have indicated that reducing the silica layer thickness is beneficial if the silica layer is to be used for radiative cooling purposes (15). Our experimental work here points to the importance of considering the thermal emission properties of layers atop the silicon absorber layer in the overall design and optimization of encapsulated solar cells.…”

Section: Discussionmentioning

confidence: 61%

“…Such a structure, being a near-perfect solar reflector, makes no use of incident sunlight. On the other hand, in many applications, including solar cells (15) and outdoor structures (16), the utilization of sunlight through absorption is intrinsic for either operational or aesthetic considerations, but the heating associated with sunlight absorption is undesirable. For these applications, lowering operating temperatures via radiative cooling is only viable if one can simultaneously preserve the absorption of sunlight.…”

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confidence: 99%

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Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody

Zhu

Raman

Fan

2015

Proc. Natl. Acad. Sci. U.S.A.

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525

351

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A solar absorber, under the sun, is heated up by sunlight. In many applications, including solar cells and outdoor structures, the absorption of sunlight is intrinsic for either operational or aesthetic considerations, but the resulting heating is undesirable. Because a solar absorber by necessity faces the sky, it also naturally has radiative access to the coldness of the universe. Therefore, in these applications it would be very attractive to directly use the sky as a heat sink while preserving solar absorption properties. Here we experimentally demonstrate a visibly transparent thermal blackbody, based on a silica photonic crystal. When placed on a silicon absorber under sunlight, such a blackbody preserves or even slightly enhances sunlight absorption, but reduces the temperature of the underlying silicon absorber by as much as 13°C due to radiative cooling. Our work shows that the concept of radiative cooling can be used in combination with the utilization of sunlight, enabling new technological capabilities.radiative cooling | thermal radiation | photonic crystal | solar absorber T he universe, at a temperature of 3 K, represents a significant renewable thermodynamic resource: it is the ultimate heat sink. Over midinfrared wavelengths, in particular between 8 and 13 μm, Earth's atmosphere is remarkably transparent to electromagnetic radiation. This wavelength range coincides with the peak wavelength of thermal radiation from terrestrial structures at typical ambient temperatures. Thus, a sky-facing terrestrial object can have radiative access to the universe. Exploiting this radiative access has led to the demonstration of radiative cooling (1-7), as well as proposals for direct electric power generation from thermal radiation of terrestrial objects (8).Whereas historically radiative cooling was largely developed for night-time applications (1-6, 9-13), recent works have achieved daytime radiative cooling (7,14). In particular, it was shown that the radiative cooling to below ambient air temperature can be achieved (7), with a photonic structure that reflects almost all incident sunlight and simultaneously emits significant thermal radiation in the midinfrared. Such a structure, being a near-perfect solar reflector, makes no use of incident sunlight. On the other hand, in many applications, including solar cells (15) and outdoor structures (16), the utilization of sunlight through absorption is intrinsic for either operational or aesthetic considerations, but the heating associated with sunlight absorption is undesirable. For these applications, lowering operating temperatures via radiative cooling is only viable if one can simultaneously preserve the absorption of sunlight.Here we experimentally demonstrate a visibly transparent thermal blackbody, based on a silica photonic crystal, using a thermophotonic approach (17-30). When placed on a silicon absorber under sunlight, such a blackbody preserves and even slightly enhances sunlight absorption, but reduces the temperature of the silicon absorber by as m...

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Section: Discussionmentioning

confidence: 61%

mentioning

confidence: 99%

Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody

Zhu

Raman

Fan

2015

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

525

351

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“…Metasurfaces that possess exceptional thermoregulatory properties have been an emerging field of research and have the potential to make an important technological impact. Fan and colleagues are pioneering the research on radiative cooling metasurfaces [244][245][246], which have strong reflectivity in the solar radiation spectrum and enhanced emissivity in the thermal radiation spectrum. Metasurfaces based on multilayered thin films have demonstrated in experiments passive cooling of objects to a few degrees below the ambient air temperature under direct sunlight [246].…”

Section: Discussionmentioning

confidence: 99%

A review of metasurfaces: physics and applications

2016

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Abstract. Metamaterials are composed of periodic subwavelength metal/dielectric structures that resonantly couple to the electric and/or magnetic components of the incident electromagnetic fields, exhibiting properties that not found in nature. This class of micro-and nano-structured artificial media have attracted great interest during the past 15 years and yielded ground-breaking electromagnetic and photonic phenomena. However, the high losses and strong dispersion associated with the resonant responses and the use of metallic structures, as well as the difficulty in fabricating the micro-and nanoscale 3D structures, have hindered practical applications of metamaterials. Planar metamaterials with subwavelength thickness, or metasurfaces, consisting of single-layer or few-layer stacks of planar structures can be readily fabricated using lithography and nanoprinting methods, and the ultrathin thickness in the wave propagation direction can greatly suppress the undesirable losses. Metasurfaces enable a spatially varying optical response (e.g., scattering amplitude, phase, and polarization), mold optical wavefronts into shapes that can be designed at will, and facilitate the integration of functional materials to accomplish active control and greatly enhanced nonlinear response. This paper reviews recent progress in the physics of metasurfaces operating at wavelengths ranging from microwave to visible. We provide an overview of key metasurface concepts such as anomalous reflection and refraction, and introduce metasurfaces based on the PancharatnamBerry phase and Huygens' metasurfaces, as well as their use in wavefront shaping and beam forming applications, followed by a discussion of polarization conversion in fewlayer metasurfaces and their related properties. An overview of dielectric metasurfaces reveals their ability to realize unique functionalities coupled with Mie resonances and their low ohmic losses. We also describe metasurfaces for wave guidance and radiation control, as well as active and nonlinear metasurfaces. Finally, we conclude by providing our opinions of future developments in this rapidly developing research field.

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“…The temperature of environment takes into our study as 25C°. the other parameters that are be using in the program putted in the table (2). …”

Section: Numerical Investigationsmentioning

confidence: 99%

“…He studied different systems of solar concentrations systems typed according to its geometry. Linxiao Zhu [2] introduces a general approach to lower the operating temperature of a solar cell, while maintaining its solar absorption at the same average. He presents an ideal scheme for the irradiative cooling of solar cells and prove that the ideal scheme can lower its operating temperature by 18.3 K. also his investigation demonstrate that a micro-photonic design based on real material properties that approaches the performance of the ideal scheme.…”

Section: Introductionmentioning

confidence: 99%

Improving of Photovoltaic Cell Performance by Cooling using Two different Types of Fins

Jobair¹

2017

IJCA

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A numerical investigation have been executed for improving the efficiency of a photovoltaic cell by using two types of fins(rectangular and triangular)at the rear of the cell to increasing the area for losing heat. The study has been executed under a certain circumstances, the variation of a fluid velocity, fin length, fin thickness and fin spacing taken into account. Under a certain circumstances the triangular fin shows a higher ability for losing heat and higher performance than the rectangular fin. The MATLAB program used in this research to ensure the results.

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Radiative cooling of solar cells

Cited by 456 publications

References 40 publications

Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody

Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody

A review of metasurfaces: physics and applications

Improving of Photovoltaic Cell Performance by Cooling using Two different Types of Fins

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