Optical properties and thermal stability of pulsed-sputter-deposited AlxOy/Al/AlxOy multilayer absorber coatings

Barshilia, Harish C.; Selvakumar, N.; Vignesh, G.; Rajam, K.S.; Biswas, A.

doi:10.1016/j.solmat.2008.11.005

Cited by 82 publications

(22 citation statements)

References 32 publications

(54 reference statements)

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“…85 Their simulation indicated that the emissivity of the periodic structure consisting of 11 unit cells with 10 nm silver and 150 nm of vacuum in the IR range could be reduced by more than two orders of magnitude compared with that of a bare 10-nm silver film. Several multilayer absorbers based on different metallic nanofilms (Al, Pt, Cr, Ti) and 86 This coating on a Cu substrate was stable at up to 400 6 C in air, and degradation occurred when the temperature exceeded 450 6 C due to the diffusion of Cu. Replacing Cu with a Mo substrate, the solar absorber was stable up to 450 6 C in air and 800 6 C in vacuum.…”

Section: Multilayer Absorbersmentioning

confidence: 99%

“…Replacing Cu with a Mo substrate, the solar absorber was stable up to 450 6 C in air and 800 6 C in vacuum. 86 Other systems such as Al x O y /Pt/Al x O y , 87 SiO 2 /Ti/SiO 2 /Al, 88 AlN/Ti/ AlN, 89 and HfO x /Mo/HfO 2 were also investigated. 90 The colored solar selective coatings in the Ti/AlN multilayer structure were obtained by adjusting the layer number and thickness.…”

Section: Multilayer Absorbersmentioning

confidence: 99%

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Metallic nanostructures for light trapping in energy-harvesting devices

et al. 2014

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Solar energy is abundant and environmentally friendly. Light trapping in solar-energy-harvesting devices or structures is of critical importance. This article reviews light trapping with metallic nanostructures for thin film solar cells and selective solar absorbers. The metallic nanostructures can either be used in reducing material thickness and device cost or in improving light absorbance and thereby improving conversion efficiency. The metallic nanostructures can contribute to light trapping by scattering and increasing the path length of light, by generating strong electromagnetic field in the active layer, or by multiple reflections/absorptions. We have also discussed the adverse effect of metallic nanostructures and how to solve these problems and take full advantage of the light-trapping effect. INTRODUCTIONThe conversion of solar energy to electricity or heat might be the ultimate means to help solve the energy crisis when hydrocarbon resources such as coal and other fossil fuels cannot satisfy the energy demand. Solar energy is abundant, ,5000 times our current power consumption.1 The use of solar energy can also reduce the environmental problems caused by the consumption of fossil fuels by reducing dusts, noxious gases and greenhouse gases, as well as the resulting haze, acid rain and global warming. To date, the worldwide installed capacity of solar harvesting devices is ,60 GW in electric energy and ,300 GW in thermal energy, 2 with an annual rapid increase. For the existing technology, there is room for further improvement by either enhancing the light absorption or avoiding loss of electricity or heat after absorption. Recently, new advances in nanotechnology and material fabrication methods have resulted in an emerging field of plasmonics by properly introducing metallic nanostructures to manipulate light, enabling light trapping in active layers and thereby enhancing the performance of energy-harvesting devices.3 In addition, certain highly absorbing surfaces or structures with broadband absorption promising to extend the working wavelength of the solar energy spectrum (Figure 1) have been realized. The light-trapping effect, however, allows the thickness of materials and the costs of solar cells to decrease, which in turn benefits electricity collection when the minor carrier diffusion length in the active layer is not sufficiently long.In this review, we focus on light trapping induced by metallic nanostructures for solar energy collection. Corresponding applications are not only for photovoltaics, but also for solar thermal. In fact, solar thermal has a market with profit even higher than photovoltaics, yet

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Section: Multilayer Absorbersmentioning

confidence: 99%

Section: Multilayer Absorbersmentioning

confidence: 99%

Metallic nanostructures for light trapping in energy-harvesting devices

et al. 2014

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“…These coatings are also able to maintain a low emittance in the range of thermal radiation from the absorber itself. There are large numbers of reports related to solar-selective coatings [7][8][9][10][11][12][13], although most of them are considered at temperatures below 500˝C. Due to a higher surface temperature with regard to the operating temperature, a much higher thermal stability is required for spectrally-selective materials.…”

Section: Introductionmentioning

confidence: 99%

A High-Temperature Solar Selective Absorber Based upon Periodic Shallow Microstructures Coated by Multi-Layers Using Atomic Layer Deposition

et al. 2016

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Regarding the fabrication of solar selective absorbers, the ability to create microstructures on top of metal surfaces is a promising technology. Typically, these materials are able to possess spectrally-selective absorption properties for high-temperature usage. Solar-selective absorbers that function at temperatures up to 700˝C and possess shallow honeycomb cylindrical microcavities coated with a metal-dielectric multi-layer have been investigated. Honeycomb array cylindrical microcavities were fabricated on W substrate with interference lithography and multi-layers consisting of Pt nano-film sandwiched by Al 2 O 3 layers were created for a uniform coating via atomic layer deposition. The absorbance spectrum of fabricated samples reveals results consistent with a simulation based on a rigorous coupled-wave analysis method. A solar absorbance value of 0.92 and a hemispherical total emittance value of 0.18 at 700˝C was determined from the fabricated solar-selective absorber. Additionally, thermal stability of up to 700˝C was confirmed in vacuum.

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“…Al x O y /Pt/Al x O y MSSAC with a tantalum diffusion barrier was also found to be thermally stable up to 700°C in air . Al x O y /Al/Al x O y MSSAC deposited on to Cu substrates exhibited good thermally stability up to 400°C in air and the coatings, which were deposited onto Mo substrates were thermally stabile up to 800°C in vacuum (Barshilia et al, 2009). Most of the MSSACs degrade at higher temperature because of interdiffusion between the layers and oxidation.…”

Section: Introductionmentioning

confidence: 99%