Performance Of Luminescent Solar Concentrators Research Articles

Aggregation-Induced Enhanced Red Emission Graphene Quantum Dots for Integrated Fabrication of Luminescent Solar Concentrators.

Graphene quantum dots (GQDs) commonly suffer from the fluorescence problem of aggregation-caused quenching under high-concentration loading or in the solid state, which seriously hinders the application. Here we report a type of GQDs with red aggregation-induced enhanced emission (AIEE). It is confirmed that the aggregation state of the AIEE GQDs is a J-aggregate. The GQDs/poly(methyl methacrylate) film presented a photoluminescence quantum yield as high as 60.81%, and the record-high performance of luminescent solar concentrators (LSCs) was achieved. The power conversion efficiency (ηPCE) is up to 8.35% and the external optical efficiency (ηext) is ∼8.99% for the GQD-based LSCs (45 mW/cm2). Even under one sun illumination (100 mW/cm2), the corresponding ηPCE and ηext values are 3.12% and 4.52%, respectively. The internal photon efficiency (ηint) of an LSC device is about 5.02%. The synthesis of AIEE GQDs bridges the research gap in the emission mechanism of AIEE in GQDs.

(Invited) Tuning the Optoelectronic Properties of Inorganic and Carbon-Based Quantum Dots for Highly Efficient Luminescent Solar Concentrators

Luminescent solar concentrators (LSCs) are an old class of devices based on semitransparent windows, in which luminophores are embedded in a transparent matrix.[1] The luminophores can absorb and re-emit solar light and are able to generate electric power by collecting the re-emitted light at the borders of the slab. In the past, lab-to-fab transition of such devices was impeded by intrinsic limitations of the luminophores in terms of low quantum yield, strong resorption due to small Stokes shift, low optical and photoconversion efficiency of the final device. In the last years, a renaissance of such devices has been driven by the development of new 0-dimensional nanostructures, with tunable optical properties, which can guarantee good performance of LSCs.[2,3] Specifically, high quantum yield can be obtained; resorption losses can be limited by modulating the Stokes shift; final color of the window can be tuned by tuning light absorption properties; UV and IR parts of solar spectrum can be exploited without affecting window transparency. We will give examples of different 0-dimensional systems, which have been developed toward high efficiency LSCs, among which inorganic quantum dots and carbon dots.[4,5] Several strategies will be illustrated to tune the optoelectronic properties of the luminophores, including doping, core-shell structuring, and surface treatments.

Diffuse radiation influence on the performance of luminescent solar concentrators

Luminescent Solar Concentrators (LSCs) are often purported to perform pretty well under both direct and diffuse solar irradiance conditions, yet the underlying rationale supporting this assumption remains scant. Furthermore, a significant portion of previous research on these photovoltaic devices relies on indoor equipment for efficiency characterization, thereby limiting insights into their performance under real operating conditions. In this study, we provide a theoretical framework elucidating the principles governing the superior performance of LSCs under diffuse irradiance. Specifically, we demonstrate that the isotropic distribution of dipoles within the LSC optical window aligns favorably with the Lambertian distribution of diffuse radiation, thereby enhancing photon absorption under diffuse conditions (25 %) respect to clear sunny skies (21 %). This theoretical foundation is bolstered by experimental investigations involving prototypes utilizing Lumogen Red dye, conducted under adverse irradiance conditions, including sunny, hazy, and partially cloudy skies. Our experimental findings reveal that light scattering, whether arising naturally from diffuse radiation or via scattering from neighboring surfaces, significantly amplifies the short-circuit current of LSC devices (37 % relative enhancement) compared to that generated under clear sky conditions (21 % relative enhancement).

Applications of ZnSe quantum dots for solar energy harvesting

To reduce the large usage of fossil fuels, scholars have made great efforts to develop green energy such as wind energy, biomass energy, and solar energy. Solar energy has special benefits, thus solar energy harvesting technologies including solar cells, luminescent solar concentrators, photocatalysis have been studied widely. It is meaningful to study the working principle of those technologies. For the special properties of ZnSe, different kinds of nanostructure of it have been used for solar energy harvesting. Among them, since quantum qot structure has some specific characters, the application of it for solar energy harvesting are worthwhile to mention. This study aims to introduce solar cells, luminescent solar concentrators, photocatalysis technologies and the applications of ZnSe quantum dots for them. It found that ZnSe quantum dots enhanced the behavior of Si nanowire solar cells. Besides, the outstanding performance of luminescent solar concentrators based on InP/ZnSe quantum dots is partly own to ZnSe shell structure. Moreover, some quantum dots including ZnSe shell structure behave good photocatalytic H2 evolution performances. At the same time, the nanostructures of the quantum dots mentioned are shown.

Mixed halide perovskite-based luminescent solar concentrator with high efficiency

Organic-Inorganic hybrids with adjustable photoluminescence, high efficacy, and good thermal stability, achieved through organic and inorganic materials, are potentially useful materials for luminescent solar concentrators (LSCs). There is currently significant interest in generating mixed halide Organic-Inorganic hybrids that emit a strong fluorescence ranging from green to red. The aim of this study is to produce LSCs by synthesis and investigation of new derivatives of mixed halide perovskites, including CH3NH3Pb(Br1−xClx)3, CH3NH3Pb(I1−xBrx)3 and CH3NH3PbI3. A major problematic loss mechanism that affects the efficiency of LSCs is the reabsorption of the emitted light by the luminophores. By altering the halogen atoms present in mixed halide perovskites, their absorption and emission wavelengths can be tuned, making them a potential solution to enhance the optical properties of luminescent solar concentrators. Additionally, the large Stokes shift observed in these materials can further contribute to improving the performance of LSCs. Also, the LSC performance was evaluated by a thorough optical and photovoltaic characterization. The findings of this study indicate that identifying the appropriate halogen atom for the synthesized perovskite structures, as well as determining the suitable concentration of the hybrids used in the LSCs, are crucial factors in achieving an efficient LSC system. It was found that CH3NH3PbBrCl2, hybrid perovskite, with 7.5 wt.% concentration in Polyvinyl Alcohol (PVA), results in the most efficient LSC with minimal reabsorption effects. The efficiency of the coated Si PV cell is increased by about 58% compared to an uncoated cell.

Environmental Effects on the Performance of Quantum Dot Luminescent Solar Concentrators.

Luminescent solar concentrators (LSCs) are all-photonic, semitransparent solar devices with great potential in the emerging fields of building-integrated photovoltaics and agrivoltaics. Over the past decade, particularly with the advent of quantum dot (QD) LSCs, tremendous progress has been made in terms of photovoltaic efficiency and device size by increasing solar spectral coverage and suppressing reabsorption losses. Despite these advances in LSC design, the effects of environmental conditions such as rain, dust, and dirt deposits, which are ubiquitous in both urban and agricultural environments, on LSC performance have been largely overlooked. Here, we address these issues by systematically investigating the environmental effects on the solar harvesting and waveguiding capability of state-of-the-art QD-LSCs, namely, the presence of airborne pollutants (dust), water droplets, and dried deposits. Our results show that dust is unexpectedly insignificant for the waveguiding of the concentrated luminescence and only reduces the LSC efficiency through a shadowing effect when deposited on the outer surface, while dust accumulation on the inner LSC side increases the output power due to backscattering of transmitted sunlight. Water droplets, on the other hand, do not dim the incident sunlight, but are detrimental to waveguiding by forming an optical interface with the LSC. Finally, dried deposits, which mimic the evaporation residues of heavy rain or humidity, have the worst effect of all, combining shading and waveguide losses. These results are relevant for the design of application-specific surface functionalization/protection strategies real LSC modules.

Ray-Trace Modeling to Characterize Efficiency of Unconventional Luminescent Solar Concentrator Geometries.

Luminescent solar concentrators (LSCs) are a promising technology to help integrate solar cells into the built environment, as they are colorful, semitransparent, and can collect diffuse light. While LSCs have traditionally been cuboidal, in recent years, a variety of unconventional geometries have arisen, for example, circular, curved, polygonal, wedged, and leaf-shaped designs. These new designs can help reduce optical losses, facilitate incorporation into the built environment, or unlock new applications. However, as fabrication of complex geometries can be time- and resource-intensive, the ability to simulate the expected LSC performance prior to production would be highly advantageous. While a variety of software exists to model LSCs, it either cannot be applied to unconventional geometries, is not open-source, or is not tractable for most users. Therefore, here we introduce a significant upgrade of the widely used Monte Carlo ray-trace software pvtrace to include: (i) the capability to characterize unconventional geometries and improved relevance to standard measurement configurations; (ii) increased computational efficiency; and (iii) a graphical user interface (GUI) for ease-of-use. We first test these new features against data from the literature as well as experimental results from in-house fabricated LSCs, with agreement within 1% obtained for the simulated versus measured external photon efficiency. We then demonstrate the broad applicability of pvtrace by simulating 20 different unconventional geometries, including a variety of different shapes and manufacturing techniques. We show that pvtrace can be used to predict the optical efficiency of 3D-printed devices. The more versatile and accessible computational workflow afforded by our new features, coupled with 3D-printed prototypes, will enable rapid screening of more intricate LSC architectures, while reducing experimental waste. Our goal is that this accelerates sustainability-driven design in the LSC field, leading to higher optical efficiency or increased utility.

High-efficiency plasmonic luminescent solar concentrators based on thiol-ene polymer

Advances in solar energy harvesting technology require innovative approaches to meet the growing energy demand. In this work, we exploit the plasmonic interaction of metal nanoparticles with fluorophores to improve the optical performance of luminescent solar concentrators (LSCs). The plasmonic luminescent solar concentrators (PLSCs) with dimensions of 5 cm × 5 cm × 0.5 cm containing CsPbBr3 quantum dots (QDs) and gold nanoparticles (Au NPs) are fabricated, characterized, and evaluated systematically. As the Au NPs concentration increases, the optical performance of PLSCs exhibits, first enhancement, and then diminishment. When the Au NPs concentration is 2 × 10−4 wt%, the optimal external quantum efficiency, optical conversion efficiency, and power conversion efficiency of the PLSC reach 1.58%, 2.90%, and 0.437%, respectively. At higher concentrations of Au NPs, the non-radiative energy transfer from the CsPbBr3 QDs to the Au NPs leads to a decrease of the emission, which can be confirmed by the decreasing lifetime of the QDs. The overall optical performance of PLSCs depends on two competing effects, excitation rate and non-radiative energy transfer efficiency. Furthermore, the PLSC demonstrate the good aesthetic quality as an excellent substitute for commercial glass. We anticipate that the high optical conversion efficiency of PLSCs based on thiol-ene polymer would shed light on future application in LSCs.

Numerical Method for Calculation of Power Conversion Efficiency and Colorimetrics of Rectangular Luminescent Solar Concentrators

Similar to conventional photovoltaics, the path toward higher efficiencies for luminescent solar concentrators (LSCs) shows increased interest in tandem structures. Herein, a numerical calculation that allows for much faster estimates of fundamental LSC performance indicators (power conversion efficiency, average visible transmission, and color‐rendering index) compared to ray trace simulations is proposed. Both double and triple structures are assessed, taking into account concentrations, absorption and emission spectra, and quantum yield as luminophore inputs for rectangular LSCs of any size. The waveguide material is modeled using an absorption spectrum and a refractive index. Interactions between the first, second, and/or third LSCs are incorporated into the algorithm. A comparison with ray trace results shows good correspondence. Supplementary Excel files are available with detailed calculations for future research or industry applications.

Modeling and comparison of bulk and thin-film luminescent solar concentrators based on colloidal perovskite quantum dots.

Photovoltaic integrated luminescent solar concentrators (LSCs) can be embedded in modern buildings to serve as power-generation units. In this Letter, we demonstrate and develop a Monte Carlo ray-tracing model and a numerical description for the performance and loss evaluation of LSCs based on colloidal quantum dots. The performance differences between bulk and thin-film LSCs are systematically analyzed at different sizes and concentrations. It is found that large-area thin-film LSCs generally perform better, which is attributed to the suppression of scattering and the retention of quantum yield by this structure with twice the performance of bulk LSCs.

Förster Resonance Energy Transfer in Luminescent Solar Concentrators.

Luminescent solar concentrators (LSCs) are an emerging technology to collect and channel light from a large absorption area into a smaller one. They are a complementary technology for traditional solar photovoltaics (PV), particularly suitable for application in urban or indoor environments where their custom colors and form factors, and performance under diffuse light conditions may be advantageous. Förster resonance energy transfer (FRET) has emerged as a valuable approach to overcome some of the intrinsic limitations of conventional single lumophore LSCs, such as reabsorption or reduced quantum efficiency. This review outlines the potential of FRET to boost LSC performance, using highlights from the literature to illustrate the key criteria that must be considered when designing an FRET‐LSC, including both the photophysical requirements of the FRET lumophores and their interaction with the host material. Based on these criteria, a list of design guidelines intended to aid researchers when they approach the design of a new FRET‐LSC system is presented. By highlighting the unanswered questions in this field, the authors aim to demonstrate the potential of FRET‐LSCs for both conventional solar‐harvesting and emerging LSC‐inspired technologies and hope to encourage participation from a diverse researcher base to address this exciting challenge.

Re-absorption-free perovskite quantum dots for boosting the efficiency of luminescent solar concentrator

Luminescent solar concentrator (LSC) is a novel sunlight manager that can collect sunlight around buildings and convert it into electrical energy. Due to their high photoluminescence quantum yields (PLQYs), lead halide perovskite quantum dots (QDs) as efficient emitters are being developed for LSC applications. However, the large overlap between absorption and emission spectra inevitably gives rise to the re-absorption, which seriously hinders the improvement of the LSC performance. To improve the optical efficiency, the re-absorption-free Mn-doped perovskite QDs have attempted to be integrated into the thiol-ene polymer for LSC applications in this work. Light propagation measurements and Monte Carlo simulations verify that the emission arising from Mn2+ ions dopant is immune from re-absorption. Benefiting from the increased PLQY and suppressed re-absorption, the Mn-doped perovskite QDs based LSCs exhibit excellent performance with an optical efficiency of up to 2.23%, which is significantly higher than that (=1.63%) of the LSC based on the pure CsPbCl3 QDs. After coupling the commercial PV cells, the optimized LSC shows a power conversion efficiency of 0.97% under the standard AM1.5 solar simulator. We anticipate that the Mn-doped perovskite QDs in the thiol-ene polymer as the efficient solar collector may pave the way to alleviate the re-absorption issue for future LSC applications.

Performance of Luminescent Solar Concentrators Integrated with Negative Replica Layers of Leaf Surface Microstructures.

In this study, a negative replica layer of leaf surface microstructures was used to cover the top surfaces of semitransparent thin-film luminescent solar concentrators (LSCs) to enhance the concentrators’ performance. With low reflection on the air–glass interface of the glass plate in a thin-film LSC, a negative replica layer enables the scattering of incident sunlight and increases the path of light transmitted into the LSC and the thin phosphor layer at the bottom surface of the LSC. The incident sunlight is therefore more likely to interact with the phosphor particles in the thin-film phosphor layer, thereby enhancing the performance of the LSC. In this study, semitransparent thin-film LSCs with different inorganic phosphors were examined. The experimental results revealed that the optical collection efficiency of semitransparent thin-film LSCs covered with negative replica layers of leaf surface microstructures was higher than that of the semitransparent thin-film LSCs without negative replica layers. Furthermore, the LSCs with negative replica layers with high haze ratios exhibited high optical collection efficiency. Integrating negative replica layers of leaf surface microstructures as semitransparent layers in thin-film LSCs may optimize the application of LSCs in building-integrated photovoltaics (BIPVs).

Red‐emitting tetraphenylethylene derivative with aggregation‐induced enhanced emission for luminescent solar concentrators: A combined experimental and density functional theory study

AbstractThis study examines the use of an aggregation‐induced enhanced emission fluorophore (TPE‐MRh) to prepare red‐emitting luminescent solar concentrators (LSCs) based on poly(methyl methacrylate) (PMMA) and poly(cyclohexyl methacrylate) (PCMA). TPE‐MRh is a tetraphenylethylene (TPE) derivative bearing two dimethylamino push groups and a 3‐methyl‐rhodanine pull moiety, with absorption maxima at around 500 nm and fluorescence peak at 700 nm that strongly increases in solid‐state. TPE‐MRh displays a typical crystallization‐induced enhanced emission that has been rationalized by modeling the compound behavior in solution and solid‐state via density functional theory calculations with the inclusion of the environment. TPE‐MRh dispersed into 5 × 5 cm2 polymer films with a thickness of 25 ± 5 μm has revealed a partial fluorescence quenching with fluorophore content. Quantum yields (QYs) below 10% for the 2 wt.% of doping have been addressed to the formation of less emissive micro‐sized clusters of fluorophores. PMMA slabs with the same surface size but 3 mm of thickness and 200 ppm of TPE‐MRh have provided QY of 36.5% thanks to the attenuation of the detrimental effects of fluorophore aggregation. This feature is reflected in the LSCs performance, with devices achieving the largest power collected by the photovoltaic cell.

Luminescent Solar Concentrators: A Review of Nanoengineering Opportunities for Reducing Surface Losses

Luminescent solar concentrators are a lesser-known solar power technology that have the potential to make their way into the constellation of building integrated photovoltaics products. A transparent plastic sheet with solar cells on its edges incorporating luminescent species acts as a wave guide to concentrate light entering through its exposed surface to smaller area photovoltaics. Although they have many advantages, the technology's low efficiency constitutes a major barrier to potential commercialization. While there are several factors contributing to this issue, the low efficiency is largely attributed to the escape cone losses through the light-receiving, large area surfaces. Advances in nanoengineering have provided new, promising ways to reduce these losses. Spectrally selective mirrors, cholesteric mirrors, photonic crystals, asymmetric light transmission interfaces, and quantum dots and dyes with anisotropic emission are all possible solutions that can be engineered at the nanoscale to reduce surface losses and improve overall performance of luminescent solar concentrators. Continued research and improvements in these fields could enable luminescent solar concentrators to become staple products for green buildings.

Preparation and Performance of Luminescent Solar Concentrator Based on Surface Plasmon Resonance Effect

Preparation and Performance of Luminescent Solar Concentrator Based on Surface Plasmon Resonance Effect

Outdoor Characterization of a Plasmonic Luminescent Solar Concentrator

Plasmonic luminescent solar concentrators (PLSCs) have been shown to enhance the optical performance and power conversion efficiency of LSCs, due to added plasmonic gain in the medium. Despite the promising outlook of a PLSC through plasmonic coupling, device characterization and performance have not been verified in the real outdoor conditions, with varying direct and diffuse solar irradiation. In this work, characterization of a PLSC device of dimensions 4.5 \(\times\) 4.5 \(\times\) 0.3 cm3 embedded with Lumogen Red 305 dye and plasmonic gain medium of gold core silver shell nano cuboids was carried out in outdoor conditions of Dublin, Ireland. Optimized PLSC device power output at different solar insolation was compared to a reference photovoltaic (PV) cell and an optimized luminescent solar concentrator (LSC) device. The effect of the solar disc position, solar insolation, PV cell surface temperature, diurnal, and seasonal variation on the performance of the PLSC device is studied. The key observation was that PLSC average power conversion efficiency was 1.4 times more than the PV cell in cloudy and diffuse solar conditions. The PLSC device performed 45% better than a PV cell in December than July, as December has higher diffuse solar irradiation. Even though the PLSC device absorbs only 31% and transmits 69% incident solar irradiation in the concerned visible range of 380–750 nm. The preliminary outdoor characterization on a small-scale PLSC establishes its viability in a diffuse to direct solar radiation ratio throughout the year as well as establishing its benefits for integration in buildings.

Perovskite luminescent solar concentrators for photovoltaics

As large-area photon collection devices designed for photovoltaics, luminescent solar concentrators (LSCs) have been proposed for more than 40 years. In recent years, the perovskite-based LSCs have received much interest for the convenient preparation process and low cost along with high quantum yields of perovskite luminophores. However, optical losses, such as non-radiative recombination loss and reabsorption loss, seriously impair the performance of LSCs and further impede the commercialization of such promising photovoltaic devices. Various strategies, such as increasing the Stokes shift and defect passivation, have been implemented to enhance the optical performance in perovskite-based LSCs. Here, we appraise the applications of perovskite luminophores in LSCs and review the typical preparation method of perovskite-based LSCs. The state-of-the-art solutions are presented to address the optical losses, leading to the demonstration of enabling high-performance perovskite-based LSCs.

Thin-Film Luminescent Solar Concentrator Based on Intramolecular Charge Transfer Fluorophore and Effect of Polymer Matrix on Device Efficiency.

Luminescent solar concentrators (LSCs) provide a transformative approach to integrating photovoltaics into a built environment. In this paper, we report thin-film LSCs composed of intramolecular charge transfer fluorophore (DACT-II) and discuss the effect of two polymers, polymethyl methacrylate (PMMA), and poly (benzyl methacrylate) (PBzMA) on the performance of large-area LSCs. As observed experimentally, DACT-II with the charge-donating diphenylaminocarbazole and charge-accepting triphenyltriazine moieties shows a large Stokes shift and limited re-absorption losses in both polymers. Our results show that thin-film LSC (10 × 10 × 0.3 cm3) with optimized concentration (0.9 wt%) of DACT-II in PBzMA gives better performance than that in the PMMA matrix. In particular, optical conversion efficiency (ηopt) and power-conversion efficiency (ηPCE) of DACT-II/PBzMA LSC are 2.32% and 0.33%, respectively, almost 1.2 times higher than for DACT-II/PMMA LSC.

Unlocking Higher Power Efficiencies in Luminescent Solar Concentrators through Anisotropic Luminophore Emission.

The luminescent solar concentrator (LSC) offers a potential pathway for achieving low-cost, fixed-tilt light concentration. Despite decades of research, conversion efficiency for LSC modules has fallen far short of that achievable by geometric concentrators. However, recent advances in anisotropically emitting nanophotonic structures could enable a significant step forward in efficiency. Here, we employ Monte Carlo ray-trace modeling to evaluate the conversion efficiency for anisotropic luminophore emission as a function of photoluminescence quantum yield, waveguide concentration, and geometric gain. By spanning the full LSC parameter space, we define a roadmap toward high conversion efficiency. An analytical function is derived for the dark radiative current of an LSC to calculate the conversion efficiency from the ray-tracing results. We show that luminescent concentrator conversion efficiency can be increased from the current record value of 7.1-9.6% by incorporating anisotropy. We provide design parameters for optimized luminescent solar concentrators with practical geometrical gains of 10. Using luminophores with strongly anisotropic emission and high (99%) quantum yield, we conclude that conversion efficiencies beyond 28% are achievable. This analysis reveals that for high LSC performance, waveguide losses are as important as the luminophore quantum yield.