Characterization and reduction of reabsorption losses in luminescent solar concentrators
TL;DR: The effects of excitation wavelength on the optical properties of a luminescent solar concentrator (LSC) containing a fluorescent organic dye (Lumogen F Rot 305) are studied and the optical efficiency is shown to depend strongly on the Stokes shift of the fluorophore.
Abstract: The effects of excitation wavelength on the optical properties (emission spectrum and quantum yield) of a luminescent solar concentrator (LSC) containing a fluorescent organic dye (Lumogen F Rot 305) are studied. Excitation at wavelengths on the long-wavelength edge of the absorption spectrum of the dye results in redshifted emission, but the quantum yield remains constant at 100%. The origin of this effect and its consequences are discussed. The extent of the long-wavelength tail of the absorption spectrum of the dye is determined and the importance in reabsorption losses is shown. The optical efficiencies and photon transport probabilities of LSCs containing either an organic dye or a rare-earth lanthanide complex are compared using ray-tracing simulations and experiment. The optical efficiency is shown to depend strongly on the Stokes shift of the fluorophore. The lanthanide complex, which has a very large Stokes shift, exhibits a higher optical efficiency than the dye (64% cf. 50%), despite its lower quantum yield (86% cf. 100%).
Citations
More filters
TL;DR: The luminescent solar concentrator (LSC) is a simple device at its heart, employing a polymeric or glass waveguide and luminecent molecules to generate electricity from sunlight when attached to a photovoltaic cell as mentioned in this paper.
Abstract: Research on the luminescent solar concentrator (LSC) over the past thirty-odd years is reviewed. The LSC is a simple device at its heart, employing a polymeric or glass waveguide and luminescent molecules to generate electricity from sunlight when attached to a photovoltaic cell. The LSC has the potential to find extended use in an area traditionally difficult for effective use of regular photovoltaic panels: the built environment. The LSC is a device very flexible in its design, with a variety of possible shapes and colors. The primary challenge faced by the devices is increasing their photon-to-electron conversion efficiencies. A number of laboratories are working to improve the efficiency and lifetime of the LSC device, with the ultimate goal of commercializing the devices within a few years. The topics covered here relate to the efforts for reducing losses in these devices. These include studies of novel luminophores, including organic fluorescent dyes, inorganic phosphors, and quantum dots. Ways to limit the surface and internal losses are also discussed, including using organic and inorganic-based selective mirrors which allow sunlight in but reflect luminophore-emitted light, plasmonic structures to enhance emissions, novel photovoltaics, alignment of the luminophores to manipulate the path of the emitted light, and patterning of the dye layer to improve emission efficiency. Finally, some possible ‘glimpses of the future’ are offered, with additional research paths that could result in a device that makes solar energy a ubiquitous part of the urban setting, finding use as sound barriers, bus-stop roofs, awnings, windows, paving, or siding tiles.
779 citations
TL;DR: In this article, the authors provide a review on the recently published research in this field and discuss the drawbacks associated with practical applications, including geometrical limitations and fabrication costs of spectrally splitting solar receivers.
Abstract: Spectral beam splitting is a promising method to achieve high efficiency solar energy conversion. Its potential applications include multi-junction PV receivers, hybrid collectors and even biomass production. Although spectral splitting receivers can achieve high theoretical conversion efficiencies, they have not yet evolved to the commercial level. In this paper, we provide a review on the recently published research in this field and discuss the drawbacks associated with practical applications. Suggestions are made which we believe will lead to improvements in optical efficiency (including geometrical limitations) and the fabrication costs of spectrally splitting solar receivers.
313 citations
TL;DR: Doped semiconductor nanocrystals are introduced as a new class of phosphors for use in luminescent solar concentrators, for the first time bounded not by luminophore self-absorption but by the transparency of the waveguide itself.
Abstract: Optical concentration can lower the cost of solar energy conversion by reducing photovoltaic cell area and increasing photovoltaic efficiency. Luminescent solar concentrators offer an attractive approach to combined spectral and spatial concentration of both specular and diffuse light without tracking, but they have been plagued by luminophore self-absorption losses when employed on practical size scales. Here, we introduce doped semiconductor nanocrystals as a new class of phosphors for use in luminescent solar concentrators. In proof-of-concept experiments, visibly transparent, ultraviolet-selective luminescent solar concentrators have been prepared using colloidal Mn2+-doped ZnSe nanocrystals that show no luminescence reabsorption. Optical quantum efficiencies of 37% are measured, yielding a maximum projected energy concentration of ∼6× and flux gain for a-Si photovoltaics of 15.6 in the large-area limit, for the first time bounded not by luminophore self-absorption but by the transparency of the waveg...
271 citations
Cites background from "Characterization and reduction of r..."
...As shown in Figure 3C, the spectral distribution of edge-emitted light shows negligible variation with increasing G, contrasting with the behavior of previously studied LSC luminophores where self-absorption produces a strong bathochromic shift in edge-emitted light with increasing G.(45) This result highlights the lack of self-absorption in doped nanocrystal LSCs....
[...]
TL;DR: The proposed illumination strategy offers improved microalgae growth without resorting to artificial light sources, reducing energy use and costs of cultivation.
133 citations
TL;DR: A leaf-inspired photomicroreactor is reported that constitutes a merger between luminescent solar concentrators (LSCs) and flow photochemistry to enable green and efficient reactions powered by solar irradiation.
Abstract: The use of solar light to promote chemical reactions holds significant potential with regard to sustainable energy solutions. While the number of visible light-induced transformations has increased significantly, the use of abundant solar light has been extremely limited. We report a leaf-inspired photomicroreactor that constitutes a merger between luminescent solar concentrators (LSCs) and flow photochemistry to enable green and efficient reactions powered by solar irradiation. This device based on fluorescent dye-doped polydimethylsiloxane collects sunlight, focuses the energy to a narrow wavelength region, and then transports that energy to embedded microchannels where the flowing reactants are converted.
110 citations
References
More filters
Book•
01 Jan 1983
TL;DR: This book describes the fundamental aspects of fluorescence, the biochemical applications of this methodology, and the instrumentation used in fluorescence spectroscopy.
Abstract: Fluorescence methods are being used increasingly in biochemical, medical, and chemical research. This is because of the inherent sensitivity of this technique. and the favorable time scale of the phenomenon of fluorescence. 8 Fluorescence emission occurs about 10- sec (10 nsec) after light absorp tion. During this period of time a wide range of molecular processes can occur, and these can effect the spectral characteristics of the fluorescent compound. This combination of sensitivity and a favorable time scale allows fluorescence methods to be generally useful for studies of proteins and membranes and their interactions with other macromolecules. This book describes the fundamental aspects of fluorescence. and the biochemical applications of this methodology. Each chapter starts with the -theoreticalbasis of each phenomenon of fluorescence, followed by examples which illustrate the use of the phenomenon in the study of biochemical problems. The book contains numerous figures. It is felt that such graphical presentations contribute to pleasurable reading and increased understand ing. Separate chapters are devoted to fluorescence polarization, lifetimes, quenching, energy transfer, solvent effects, and excited state reactions. To enhance the usefulness of this work as a textbook, problems are included which illustrate the concepts described in each chapter. Furthermore, a separate chapter is devoted to the instrumentation used in fluorescence spectroscopy. This chapter will be especially valuable for those perform ing or contemplating fluorescence measurements. Such measurements are easily compromised by failure to consider a number of simple principles."
28,073 citations
TL;DR: Perylene bisimide dyes and their organization into supramolecular architectures through hydrogen-bonding, metal ion coordination and pi-pi-stacking is discussed; further self-assembly leading to nano- and meso-scopic structures and liquid-crystalline compounds is also addressed.
2,016 citations
"Characterization and reduction of r..." refers background in this paper
...In the absence of bulky substituents, such as phenoxy groups, in the bay area, perylene bisimides tend to form sandwich-typeH-aggregates [44], which show blueshifted absorption spectra and greatly reduced PLQYs, relative to the monomer....
[...]
TL;DR: In this article, the luminescence properties of 41 different Eu(III) and Tb(III), chelates that were synthesized with the purpose of developing new markers for chemical and biochemical applications were measured in aqueous solution and their suitability for labels in time resolved immunoassays were evaluated.
1,466 citations
TL;DR: In this paper, the applicability of the well-known Judd-Ofelt theory to the emissive properties of Eu3+ complexes is investigated, and it is demonstrated experimentally that the radiative lifetime of the 5D0 excited state of the Eu 3+ can be calculated directly from its corrected emission spectrum, without using Judd-ofelt theory.
Abstract: Although luminescent complexes of lanthanide ions and organic ligands have been studied intensively, relatively little attention has been paid to the natural (or ‘radiative’) lifetime of the lanthanide centered luminescent state in these systems. Here, the applicability of the well-known Judd–Ofelt theory to the emissive properties of Eu3+ complexes is investigated. Moreover, it is demonstrated experimentally that the radiative lifetime of the 5D0 excited state of Eu3+ can be calculated directly from its corrected emission spectrum, without using Judd–Ofelt theory. We also discuss briefly the possibility of finding the natural lifetimes of lanthanide ions other than Eu3+.
1,142 citations
"Characterization and reduction of r..." refers background in this paper
...Because of the energy transfer mechanism between their absorbing ligands and emitting ions [25,26], they can exhibit large Stokes shifts....
[...]
700 citations
"Characterization and reduction of r..." refers background in this paper
...Luminescent solar concentrators (LSCs) [1–5] were proposed more than 30 years ago [5] as a nonimaging means of concentrating solar radiation....
[...]
...With some of the excess photon energy being deposited in the LSC, rather than in the cells, this leads to higher cell efficiencies [5,6]....
[...]