Dish/photovoltaic cavity converter (PVCC) system for ultimate solar-to-electricty conversion efficiency-general concept and first performance predictions

Ortabasi, U.; Lewandowski, A.; McConnell, R.; Aiken, D.; Sharps, P.L.; Bovard, Bertrand G.

doi:10.1109/pvsc.2002.1190925

Cited by 9 publications

(8 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus a spectrum-splitting design that incorporates back reectors for each subcell with radiative coupling between subcells and/or light trapping could provide a signicant increase in efficiency over previously studied designs. 16,21,22,33,34 Our analysis and experimental results show the important role of radiative coupling and how spectral window and optical environment dictate the performance of subcells in a multijunction cell. As the number of subcells increases, the photon ux each subcell receives will decrease, reducing the power it converts, and this dependence is exacerbated when there is a lack of photon recycling between subcells.…”

Section: -30mentioning

confidence: 88%

Multijunction solar cell efficiencies: effect of spectral window, optical environment and radiative coupling

Eisler

Abrams

Sheldon

et al. 2014

Energy Environ. Sci.

View full text Add to dashboard Cite

Solar cell efficiency is maximized through multijunction architectures that minimize carrier thermalization and increase absorption. Previous proposals suggest that the maximum efficiency for a finite number of subcells is achieved for designs that optimize for light trapping over radiative coupling. We instead show that structures with radiative coupling and back reflectors for light trapping, e.g. spectrum-splitting cells, can achieve higher conversion efficiencies. We model a compatible geometry, the polyhedral specular reflector. We analyze and experimentally verify the effects of spectral window and radiative coupling on voltage and power. Our results indicate that radiative coupling with back reflectors leads to higher efficiencies than previously studied architectures for practical multijunction architectures (i.e., #20 subcells).The photovoltaic community is closer than ever to achieving ultra-high multijunction solar cell efficiencies (>50%).1-8 Subcells from III-V compound semiconductors are approaching ideal Shockley-Queisser behavior and emit signicant radiation of photons with energies equal to or above the optical bandgap because nonradiative recombination has been minimized with advanced growth processes.6,9 The optical environment of a solar cell controls where the radiated photons from a subcell are directed and this greatly affects its efficiency.2,3 Thus the optical design of multijunction architectures is crucial for maximizing performance. To date, (1) light trapping and (2) radiative coupling have been investigated as promising optical design strategies. Light trapping inhibits the radiative emission of a subcell in order to reduce the dark current and increase voltage.For example, this can be achieved by including a back reector on a cell.9 By contrast, radiative coupling directs radiative emission between neighboring subcells for reconversion. 2,8Cells that have a high degree of radiative coupling have higher currents and are more tolerant of spectral mismatch because photons can be redistributed and boost carrier generation in the current-limited subcells.10-15 Thus including both strong light trapping and radiative coupling could yield very high efficiencies. However, only geometries that optimize for either strong light trapping or strong radiative coupling have been considered in the previous literature.2 Until now, a proposed structure that only optimizes for light trapping and completely blocks radiative coupling using frequency selective reectors matched to the band gap emission of each subcell has been assumed to be the most efficient structure for discrete numbers of junctions. This 'selective reector' design has been shown to give the highest efficiencies for time symmetric structures comprised of a realistic number Broader contextEven with the recent advances in photovoltaics research, 50% solar cell efficiencies have not yet been achieved. Previous designs have focused on a tandem stack structure where semiconductor layers are epitaxially grown or wafer bonded on top of e...

show abstract

Section: -30mentioning

confidence: 88%

Multijunction solar cell efficiencies: effect of spectral window, optical environment and radiative coupling

Eisler

Abrams

Sheldon

et al. 2014

Energy Environ. Sci.

View full text Add to dashboard Cite

show abstract

“…For instance, systems with four cells have been built [10,12,13] and efficiencies exceeding 43% were achieved. Systems with five cells are under development and are likely to surpass the 43% value [14].…”

Section: Introductionmentioning

confidence: 99%

An optical arrangement for boosting the efficiency of a system containing a GaAs solar cell

Mokri¹,

Emziane²

2014

2014 First International Conference on Green Energy ICGE 2014

View full text Add to dashboard Cite

GaAs solar cells exceed 28% efficiency under no light concentration, and this is partly due to their near-optimum bandgap of 1.42 eV. Also, the electrical and optical properties of GaAs enable efficient generation and collection of free carries excited by photons with wavelengths below 870 nm. However, this part of the spectrum represents less than 40% of the total solar spectrum, and the remaining 60% is not utilized. The purpose of this research is to convert this part of the spectrum to enhance the efficiency of the GaAs cell. This is achieved by proposing an optical arrangement that splits the solar spectrum at the wavelength 870 nm, and direct the normally not utilized part of the spectrum towards a single-junction thermophotovoltaic cell. Several medium and low energy bandgap materials are considered, and based on their I-V parameters, the optimal configuration of the proposed optical design is decided. Around 40% improvement in efficiency has been achieved by combining the GaAs cell with an InGaAs cell in the proposed optical arrangement.

show abstract

“…More recently different approaches have emerged like [13] where a light trapping assembly, two dichroic mirrors and 3 solar cells could achieve 34% efficiency. A cavity receiver where a cavity and multiple rugate filters promise ultimate efficiencies [14,15]. Diffraction based holographic optical elements (HOE) have been considered for spectral splitting due to their high dispersion [16,17].…”

Section: Introductionmentioning

confidence: 99%

Single element spectral splitting solar concentrator for multiple cells CPV system

Stefancich¹,

Zayan²,

Chiesa³

et al. 2012

Opt. Express

View full text Add to dashboard Cite

Shockley Read Hall equation poses a limit to the maximum conversion efficiency of broadband solar radiation attainable by means of a single bandgap converter. A possible approach to overcome such a limit is to convert different parts of the broadband spectrum using different single junction converters. We consider here a different modus operandi where a single low-cost optimized plastic prismatic structure performs simultaneously the tasks of concentrating the solar light and, based on the dispersive behavior of the employed material, spatially splitting it into its spectral component. We discuss its approach, optical simulations, fabrication issues and preliminary experimental results demonstrating its feasibility for cost effective high efficiency Concentrated Photovoltaic Systems (CPV) systems.

show abstract

Dish/photovoltaic cavity converter (PVCC) system for ultimate solar-to-electricty conversion efficiency-general concept and first performance predictions

Cited by 9 publications

References 0 publications

Multijunction solar cell efficiencies: effect of spectral window, optical environment and radiative coupling

Multijunction solar cell efficiencies: effect of spectral window, optical environment and radiative coupling

An optical arrangement for boosting the efficiency of a system containing a GaAs solar cell

Single element spectral splitting solar concentrator for multiple cells CPV system

Contact Info

Product

Resources

About