Efficiency Of Luminescent Solar Concentrators Research Articles

Predicting the efficiency of luminescent solar concentrators for solar energy harvesting using machine learning

Building-integrated photovoltaics (BIPV) is an emerging technology in the solar energy field. It involves using luminescent solar concentrators to convert traditional windows into energy generators by utilizing light harvesting and conversion materials. This study investigates the application of machine learning (ML) to advance the fundamental understanding of optical material design. By leveraging accessible photoluminescent measurements, ML models estimate optical properties, streamlining the process of developing novel materials, offering a cost-effective and efficient alternative to traditional methods, and facilitating the selection of competitive materials. Regression and clustering methods were used to estimate the optical conversion efficiency and power conversion efficiency. The regression models achieved a Mean Absolute Error (MAE) of 10%, which demonstrates accuracy within a 10% range of possible values. Both regression and clustering models showed high agreement, with a minimal MAE of 7%, highlighting the efficacy of ML in predicting optical properties of luminescent materials for BIPV.

Luminescent solar concentrator efficiency enhanced via nearly lossless propagation pathways

AbstractLuminescent solar concentrators (LSCs) have the potential to serve as energy-harvesting windows in buildings. Although recent advances in nanotechnology have led to the emergence of novel fluorophores such as quantum dots, perovskites and others, the commercialization of such functional glass remains immature due to an insufficient power conversion efficiency. In other words, improvements in fluorophores alone cannot fully maximize the potential of LSCs. Here we introduce a new laminated type of LSC structure where a patterned low-refractive-index medium acts as an optical ‘guard rail’, providing a practically non-decaying path for guiding photons. We also propose the design rules regarding the dimensions of LSCs and the spectral characteristics of fluorophores. Once these rules were applied, we achieved record-high LSC performance. The measured external quantum efficiencies at 450 nm are 45% for a 100 cm2 area and 32% for the LSC with an edge aspect ratio of 71. The device efficiency is 7.6%, the highest value ever reported, to the best of our knowledge. These findings may have industrial implications and could accelerate the commercialization of LSCs.

Constructing highly efficient and ultra-stable (against Temperature, Humidity and Sunlight) luminescent solar concentrators by using dendritic CsPbBr3@SiO2 particles

Conventional perovskite quantum dots (PQDs) suffer long-term stability, further limiting practical application of luminescent solar concentrators (LSCs). In this work, novel dendritic CsPbBr3@SiO2 particles with bright solid-state green light emission and 46 % of photoluminescence quantum yield (PLQY) have first been synthesized via one-step solid-phase calcination method. The dendritic CsPbBr3@SiO2 particles have then been used as fluorescent material for construction of LSCs along with using organosilicon polymers with better compatibility as waveguide materials. Single-layer thin film LSCs and overall curing LSCs are easily prepared by the casting and curing method, exhibiting high external optical efficiency (ηopt) of 7.88 % and 10.92 %, respectively. The maximum internal quantum efficiency (ηint) of thin film LSCs and overall curing LSCs reach 45.09 % and 44.07 %, respectively, while their maximum external quantum efficiency (ηext) of 29.42 % and 34.07 % are obtained, respectively. Importantly, both types of LSCs show excellent stability, maintaining above 92 % of the initial ηopt under high-relative-humidity (RH = 90 %), high-temperature (60 °C) and sunlight exposure conditions for two weeks or room temperature environment for twenty weeks. Moreover, both types of LSCs at optimal conditions have good transparency (>40 % over 515 nm of light wavelength). Otherwise, both types of LSCs have higher ηopt than that of the previous related work.

Theoretical investigation of asymmetric light interfaces for increasing optical efficiency of luminescent solar concentrators via integration of finite element simulation results with Monte Carlo ray tracing

Theoretical investigation of asymmetric light interfaces for increasing optical efficiency of luminescent solar concentrators via integration of finite element simulation results with Monte Carlo ray tracing

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.

Down-converting luminescent optoelectronics and their applications

Luminescent materials and optoelectronics, particularly those that rely on down-conversion optical phenomena (i.e., involving a conversion from higher-energy photons into lower-energy photons), have garnered increasing interest in various photonics applications. Over the years, a plethora of down-converting luminescent materials have been actively explored, in particular for enhancing the collection and conversion efficiency of luminescent solar concentrators since the 1980s. However, with the exploration of new down-converting luminescent materials and the recent development of numerous emerging applications utilizing luminescent components for enhanced system performance, the technology is envisaged to expand beyond its use in luminescent solar concentrators. This perspective article aims at shedding light on the significance of incorporating luminescent materials and components for various emerging technologies related to optical-based communication, imaging, tracking, sensing, and data storage and encryption. The related opportunities and challenges are also outlined, which can potentially inspire practical pathways toward the commercialization of luminescent-based optoelectronics and shape the way forward for the broader community.

Achieving High-Efficiency Large-Area Luminescent Solar Concentrators.

Luminescent solar concentrators (LSCs) are semitransparent windows that are able to generate electricity from sunlight absorption. LSCs have shown huge promise for realizing building-integrated photovoltaics (BIPV). Unfortunately, to date, the power conversion efficiency (PCE) of LSCs is still very low which dramatically hampers their practical applications. In this Perspective, We summarize and review the latest developments of LSCs by looking at different structures. Among others, we focus more on the next developments in the field of LSCs, i.e., the possibility of high PCE, large area, mass production, and durability needed for future industrial development. We hope to promote the application of uniform testing standards and to draw attention to industrial development, toxicity, and durability. Then, we will provide a critical assessment of the field of LSCs. Finally, the challenge and solution will be discussed.

Boosting efficiency of luminescent solar concentrators using ultra-bright carbon dots with large Stokes shift.

Luminescent solar concentrators (LSCs) are able to collect sunlight from a large-area to generate electric power with a low cost, showing great potential in building-integrated photovoltaics. However, the low efficiency of large-area LSCs caused by the reabsorption losses is a critical issue that hampers their practical applications. In this work, we synthesized novel yellow emissive carbon dots (CDs) with a large Stokes shift of 193 nm, which exhibit nearly zero reabsorption. The quantum yield (QY) of the yellow emitting CDs is up to 61%. The yellow emitting CDs can be employed to fabricate high-performance large-area LSCs due to successful suppression of the reabsorption losses. The as-prepared LSCs are able to absorb 14% of the sunlight as the absorption of the CDs matches well with the sun's spectrum. The large-area LSC (10 × 10 cm2) with a laminated structure based on the yellow emitting CDs achieves an optical conversion efficiency (ηopt) of 4.56% and power conversion efficiency (ηPCE) of 4.1% under natural sunlight (45 mW cm-2), which are significantly higher than other previously reported works with similar sizes. Furthermore, the prepared high-performance LSCs show good stability. This method of synthesizing novel CDs for high-efficiency LSCs provides a useful platform for future study and practical application of LSCs.

Boosting the efficiency of luminescent solar concentrator devices based on CH3NH3PbBr3 perovskite quantum dots via geometrical parameter engineering and plasmonic coupling

In this paper luminescent solar concentrators (LSCs) based on CH 3 NH 3 PbBr 3 perovskite quantum dots (QDs) and QDs containing gold nanoparticles (NPs) with flat and half-cylindrical geometries are introduced. Excitonic and PL emission peaks at 512 nm and 539 nm with majority average size of 16 nm are the characteristics of the synthesized lead bromide perovskite QDs. Incorporation of synthesized spherical gold NPs with an average diameter of 13 nm and absorption peak at 527 nm in perovskite based LSCs are also investigated. The measured reabsorption loss is decreased for LSCs in the presence of gold NPs. The PCE of edge-mounted solar panel in sheet LSCs based on gold NPs doped QDs, is enhanced with respect to CH 3 NH 3 PbBr 3 QD based LSCs, due to plasmonic effect of gold NPs. Varying the LSC geometry to half-cylinder improves the device performance by effectively concentrating of incident light into the solar panel. The effect of backscatterers is also investigated for bottom-mounted solar panel in new half-cylindrical geometry. The best device efficiency is obtained for the white backgrounded LSC, since it could act as a scatter to send back the lost light into the LSC, efficiently. • Lead bromide based Luminescent solar concentrators (LSCs) are fabricated in flat sheet and novel half-cylindrical geometries. • Doping Au NPs to perovskite QDs decreases the reabsorption and boosts the overall output power of LSC devices. • The PCE of half-cylindrical LSC devices are higher than sheet LSCs, due to the lens-like behavior of half-cylinders. • The white back scatterer improves the efficiency of half-cylindrical LSC devices more than mirror and black scatterers.

Engineering high-emissive silicon-doped carbon nanodots towards efficient large-area luminescent solar concentrators

Luminescent solar concentrators (LSCs) are devices that can collect sunlight from a large area, concentrating it at the borders of the slab, to achieve efficient photovoltaic conversion when small area solar cells are placed at their edges, realizing building-integrated photovoltaics. Efficient luminophores in terms of high luminescence quantum yield are needed to obtain high-performance LSCs. A key point is the ability to engineer the Stokes shift (i.e. the difference between the maximum of the absorption and emission spectra), to minimize reabsorption processes. In this work, we report novel silicon-doped carbon nanodots (Si-CDs) with an ultrahigh quantum yield (QY) up to 92.3% by a simple hydrothermal method. Thin-film structured LSCs (5 × 5 × 0.2 cm3) with different concentrations of Si-CDs are prepared by dispersing the Si-CDs into polyvinyl pyrrolidone (PVP) matrix, and the optimal power conversion efficiency (PCE) of LSCs can be as high as 4.36%, which is nearly 2.5 times higher than that prepared with silicon-undoped CDs. This Si-CDs/PVP film LSC has a high QY of 80.5%. A large-area LSC (15 × 15 cm2) is also successfully fabricated, which possesses a PCE of 2.06% under natural sunlight irradiation (35 mW·cm−2), one of the best reported values for similar size LSCs. The efficient Si-CDs as luminescent substances for high-efficiency large-area LSCs will further give an impetus to the practical exploitation of LSCs.

Construction of highly efficient carbon dots-based polymer photonic luminescent solar concentrators with sandwich structure

The enhancement of photoluminescence (PL) emission and waveguide play a key role in improving the optical efficiency of luminescent solar concentrators (LSCs). In this work, to boosting PL emission and waveguide simultaneously, one photonic crystal (PC) structure (crystalline colloid arrays (CCAs)) was introduced into carbon dots (CDs)-based polymer LSCs. A sandwich-structured CDs-based polymer photonic LSC, comprising glass/CDs-based polymer PC film/glass, was created. First, CDs-based colloidal crystal suspensions were prepared by co-assembly of monodispersed p(MMA-NIPAm) colloids and multicolor-emitting CDs in HEMA monomer induced by the evaporation-driven assembly. The obtained suspensions not only had uniform PL and structural colors, but showed enhanced PL emission. Second, the above suspensions were sandwiched between two glass sheets and finally a photonic polymer LSC with sandwiched structure (25 × 25 × 1.8 mm3) were formed via one-step photopolymerization technique. Remarkably, the optimal CDs-based polymer photonic LSCs with sandwiched structure not only had high transparence at visible range (>60%), but exhibited PL emission enhancement (at least 2 times). Furthermore, the maximum external optical efficiency (η opt ) of 5.84% could be achieved based on yellow-emitting CDs-based polymer photonic LSC. The high external optical efficiency was mainly attributed to the PL emission enhancement and good PC waveguide.

Renewable energy for a green future: Electricity produced from efficient luminescent solar concentrators

This article proposes an overarching review of the technologies engaged in world wide energy demand which uses from non-renewable to renewable energies. The electricity generated from renewable systems is largely reducing CO2 emissions, one of the greenhouse gasses realesed from non-renewable energy sources that contribute to the global warming. The photovoltaic (PV) system is the technology with stronger potential to produce affordable electricity using solar energy. Therefore, we are focusing on the PVs regarding i) how they are assembled, ii) the energy losses from spectral mismatches, and iii) the improvements of their efficiencies by several ways, which include the connection of PVs with new techologies, e.g. the luminescent solar concentrator (LSC). Recent studies have reported advantages of applying LSCs connected to PVs’ cells, as well as some strategies for minimizing or eliminating self-absorption losses. Moreover, some efficiency meters evaluate LSCs’ operation. Guided by mainly recent researches, this article approaches flexibility, low cost, easy fabrication, and great efficiency of LSCs, the main goal for the PVs’ productions upon power electricity demand.

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.

Elliptic Array Luminescent Solar Concentrators for Combined Power Generation and Microalgae Growth

The full utilization of broadband solar irradiance is becoming increasingly useful for applications such as long-term space missions, wherein power generation from external sources and regenerative life support systems are essential. Luminescent solar concentrators (LSCs) can be designed to separate sunlight into photosynthetically active radiation (PAR) and non-PAR to simultaneously provide for algae cultivation and electric power generation. However, the efficiency of LSCs suffers from high emission losses. In this work, we show that by shaping the LSC in the form of an elliptic array, rather than the conventional planar configuration, emission losses can be drastically reduced to the point that they are almost eliminated. Numerical results, considering the combined effects of emission, transmission and surface scattering losses show the optical efficiency of the elliptic array LSC is 63%, whereas, in comparison, the optical efficiency for conventional planar LSCs is 47.2%. Further, results from numerical simulations show that elliptic array luminescent solar concentrators can convert non-PAR and green-PAR to electric power with a conversion efficiency of ~17% for AM1.5 and 17.6% for AM0, while transmitting PAR to an underlying photobioreactor to support algae cultivation.

Monte Carlo simulation of a LSC based on stacked layers of fiber arrays with core-coating different absorbing properties.

In this work, a Monte Carlo ray-tracing model for the simulation and optimization of a fiber Luminescent Solar Concentrator (LSC) based on stacked layers of fiber arrays is developed and validated. The fiber LSC efficiency improvements are compared against a conventional planar LSC. We developed a new model to analyze the performance of different configurations of bulk-doped fibers and fibers constituted by a doped coating and a passive core. These configurations are analyzed also varying fiber packing geometry diameters, and length. Due to the exceptionally low absorption coefficient of the silica fibers (αwg ≈ 10-4 cm-1), concentration factors of up to 1.9 are predicted when dimensions are scaled over 1 m2, which improve more than twice the maximum concentration factor ever reported. These results serve as a preliminary theoretical study for the future development of a new LSC design based on flexible silica micro-fibers coated with Si-QDs doped poly(lauryl methacrylate) (PLMA) layers.

Enhanced luminescent solar concentrator efficiency by Foster resonance energy transfer in a tunable six‐dye absorber

Enhanced luminescent solar concentrator efficiency by Foster resonance energy transfer in a tunable six‐dye absorber

EFFECT OF DYE CONCENTRATION ON PATTERNED LUMINESCENT SOLAR CONCENTRATOR

The present paper investigates the Luminescent Solar Concentrator (LSC) with single and dual waveguide coated with perylene dye of various concentrations. Monte Carlo simulations are carried out to assess the efficiency of the LSC with the waveguide areas varying from 10 to 110 cm2, and the dye concentration varying from 30 to 800 PPM. The percentage of dye area coated in the waveguides is varied from 20 to 80%. Results indicate that the LSC efficiency increases with dye concentration up to a particular value, and thereafter shows a decreasing trend. Further, LSC efficiency is found to be increasing with a decrease in waveguide size. Experimental and simulation results indicate the maximum efficiency at the dye coverage area of 50%. Simulation results indicate the maximum LSC efficiency of around 9%, while the same is around 6% when examined experimentally.

Red and yellow emissive carbon dots integrated tandem luminescent solar concentrators with significantly improved efficiency.

Luminescent solar concentrators (LSCs) can collect solar light from a large area and concentrate it on their small-area edges mounted with solar cells for efficient solar-to-electricity conversion. Thus, LSCs show huge promise for realizing building-integrated photovoltaics because of their semi-transparency and light weight. However, the low optical efficiency of LSCs becomes a great obstacle for their application in real energy conversion. Herein, yellow emissive carbon dots with a record-breaking ultrahigh quantum yield of up to 86.4% were prepared via a simple hydrothermal approach using low-cost precursors. By combining them with red emissive carbon dots (quantum yield of 17.6%), a large area (∼100 cm2) tandem LSC was fabricated. The power conversion efficiency (PCE) of the large-area carbon dot-integrated tandem LSC reaches up to 3.8%, which is among the best reported in literature for a similar lateral size of LSCs. In particular, the tandem structure based on two laminated layers is novel, and is fit for the real structural application of keeping windows warm, where two glass slides are usually used. The high-efficiency tandem LSC using eco-friendly carbon dots as fluorophores paves way for real applications of LSCs.

High-Performance Luminescent Solar Concentrators Based on Poly(Cyclohexylmethacrylate) (PCHMA) Films

In this study, we report on the use of poly(cyclohexylmethacrylate) (PCHMA) as an alternative to the commonly used poly(methylmethacrylate) (PMMA) for the design of efficient luminescent solar concentrators (LSCs). PCHMA was selected due to its less polar nature with respect to PMMA, a characteristic that was reported to be beneficial in promoting the fluorophore dispersibility in the matrix, thus maximizing the efficiency of LSCs also at high doping. In this sense, LSC thin films based on PCHMA and containing different contents of Lumogen F Red 305 (LR, 0.2–1.8 wt%) demonstrated optical efficiencies (ηopt) comprising between 9.5% and 10.0%, i.e., about 0.5–1% higher than those collected from the LR/PMMA systems. The higher LR/polymer interactions occurred using the PCHMA matrix maximized the solar harvesting characteristics of the fluorophore and limited the influence of the adverse dissipative phenomena on the fluorophore quantum efficiency. These effects were also reflected by varying the LSC film thickness and reaching maximum ηopt of about 11.5% in the case of PCHMA films of about 30 µm.

Soft luminescent solar concentrator film with organic dye and rubbery matrix

AbstractWe propose a soft luminescent solar concentrator (LSC) with superior light propagation. The rubbery poly(ethylene‐co‐vinyl acetate) (EVA) was adopted to replace the conventional brittle poly(methyl methacrylate) (PMMA). We analyzed the transmittance, photoluminescence efficiency, crystallinity, and surface properties of LSC to understand the optical and structural properties of the LSC. In addition, we modified the optical slab model to provide insights into the optical phenomenon in plate‐type LSC devices; we evaluated the solar absorption efficiency of the glass and emitting layers. We also evaluated the solar concentration performances of the LSC devices by measuring the photocurrent density generated using a monocrystalline silicon solar cell. We compared the transporting ability of emitted light into an edge by calculating the collection efficiency based on the concentration factor and optical efficiencies (absorption and photoluminescence). The concentration factor, optical efficiency, and collection efficiency of the EVA‐LSC with 4000 ppm of Lumogen F Red 305 were 0.31, 3.1, and 40%, respectively. The overall optical properties of the EVA‐LSC were comparable to those of the PMMA‐LSC. Moreover, the light decay property of EVA‐LSC was superior by 1.2 times than PMMA‐LSC. Therefore, we suggest EVA can replace PMMA and be used for flexible and large‐area LSC applications.