Very low-emittance solar selective surfaces using new film structures

Zhang, Qi-Chu; Mills, David

doi:10.1063/1.351510

Cited by 111 publications

(42 citation statements)

References 44 publications

(1 reference statement)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Simulations indicated that the double layer cermet film exhibits a higher conversion efficiency compared with the uniform cermet or graded cermet film. 96 The double-cermet layer structure consisting of a AlN top layer, a cermet layer with a low metal volume fraction, and another cermet layer with a high metal volume fraction exhibited a high solar absorptance of 0.953 and a near-normal emittance of 0.051 for W-AlN cermet 97 and 0.933 and 0.025, respectively, for SS-AlN cermet. 98 The W-and SSAlN cermet films offer the advantage of the high reactivity of aluminum with nitrogen.…”

Section: Multilayer Absorbersmentioning

confidence: 98%

Metallic nanostructures for light trapping in energy-harvesting devices

et al. 2014

View full text Add to dashboard Cite

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

show abstract

Section: Multilayer Absorbersmentioning

confidence: 98%

Metallic nanostructures for light trapping in energy-harvesting devices

et al. 2014

View full text Add to dashboard Cite

show abstract

“…A cermet consists of nanoscale metal particles embedded within ceramic binders [30]. Typical ceramic binder materials include alumina (Al 2 O 3 ) [41], silicon dioxide (SiO 2 ), aluminum oxynitride (AlON) [8] and zirconium dioxide (ZrO 2 ) [42]. The cermet layer by itself has strong solar absorption and high transmission in the mid-IR.…”

Section: Metal-dielectric Composite Selective Solar Absorbersmentioning

confidence: 99%

Solar thermophotovoltaics: reshaping the solar spectrum

et al. 2016

View full text Add to dashboard Cite

Abstract:Recently, there has been increasing interest in utilizing solar thermophotovoltaics (STPV) to convert sunlight into electricity, given their potential to exceed the Shockley-Queisser limit. Encouragingly, there have also been several recent demonstrations of improved systemlevel efficiency as high as 6.2%. In this work, we review prior work in the field, with particular emphasis on the role of several key principles in their experimental operation, performance, and reliability. In particular, for the problem of designing selective solar absorbers, we consider the trade-off between solar absorption and thermal losses, particularly radiative and convective mechanisms. For the selective thermal emitters, we consider the tradeoff between emission at critical wavelengths and parasitic losses. Then for the thermophotovoltaic (TPV) diodes, we consider the trade-off between increasing the potential short-circuit current, and maintaining a reasonable opencircuit voltage. This treatment parallels the historic development of the field, but also connects early insights with recent developments in adjacent fields. With these various components connecting in multiple ways, a system-level end-to-end modeling approach is necessary for a comprehensive understanding and appropriate improvement of STPV systems. This approach will ultimately allow researchers to design STPV systems capable of exceeding recently demonstrated efficiency values.

show abstract

“…Since then, to achieve the spectral selectivity, various materials and structures such as the semiconductor, composite media, absorber-reflector tandem, and the materials with the rough or porous surface, cermet and multilayer films have been studied as the practical approaches for the solar selective absorber design and construction [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Among these materials and structures, the multilayer-film-based structures are of special interest because of their good spectral properties and high thermal stability [9,10], which makes them particularly suitable for the photo-thermal solar energy conversion applied under the medium and high temperature conditions.…”

Section: Introductionmentioning

confidence: 99%

Nano-Cr-film-based solar selective absorber with high photo-thermal conversion efficiency and good thermal stability

Zhou

Shen

et al. 2012

Opt. Express

View full text Add to dashboard Cite

Optical properties and thermal stability of the solar selective absorber based on the metal/dielectric four-layer film structure were investigated in the variable temperature region. Numerical calculations were performed to simulate the spectral properties of multilayer stacks with different metal materials and film thickness. The typical four-layer film structure using the transition metal Cr as the thin solar absorbing layer [SiO 2 (90nm)/Cr(10nm)/SiO 2 (80nm)/Al (≥100nm)] was fabricated on the Si or K9 glass substrate by using the magnetron sputtering method. The results indicate that the metal/dielectric film structure has a good spectral selective property suitable for solar thermal applications with solar absorption efficiency higher than 95% in the 400-1200nm wavelength range and a very low thermal emittance in the infrared region. The solar selective absorber with the thin Cr layer has shown a good thermal stability up to the temperature of 873K under vacuum atmosphere. The experimental results are in good agreement with the calculated spectral results. KeywordsSolar Energy, Thermo-optical materials, Multilayers, Thin films, optical properties Abstract: Optical properties and thermal stability of the solar selective absorber based on the metal/dielectric four-layer film structure were investigated in the variable temperature region. Numerical calculations were performed to simulate the spectral properties of multilayer stacks with different metal materials and film thickness. The typical four-layer film structure using the transition metal Cr as the thin solar absorbing layer [SiO 2 (90nm)/Cr(10nm)/SiO 2 (80nm)/Al (≥100nm)] was fabricated on the Si or K9 glass substrate by using the magnetron sputtering method. The results indicate that the metal/dielectric film structure has a good spectral selective property suitable for solar thermal applications with solar absorption efficiency higher than 95% in the 400-1200nm wavelength range and a very low thermal emittance in the infrared region. The solar selective absorber with the thin Cr layer has shown a good thermal stability up to the temperature of 873K under vacuum atmosphere. The experimental results are in good agreement with the calculated spectral results.

show abstract

Very low-emittance solar selective surfaces using new film structures

Cited by 111 publications

References 44 publications

Metallic nanostructures for light trapping in energy-harvesting devices

Metallic nanostructures for light trapping in energy-harvesting devices

Solar thermophotovoltaics: reshaping the solar spectrum

Nano-Cr-film-based solar selective absorber with high photo-thermal conversion efficiency and good thermal stability

Contact Info

Product

Resources

About