Luminescent Solar Concentrators

LSCs of various sizes and materials under Ultraviolet illumination

Luminescent Solar Concentrators (LSCs) are sheets of plastic or glass, doped with fluorescent materials, which can collect and concentrate light from large areas to their edges, as shown in Figure 1. The light can then be converted into electricity by solar cells installed at their edges. LSCs have attracted significant attention due to their ability to achieve high concentration of light, even diffuse.

Figure 1 - LSCs of various sizes and materials under Ultraviolet illumination

Depending on the users' desires, LSCs can be designed in a range of colours, transparencies, shapes, and sizes. As such, LSCs can be integrated into a range of applications, from architecture and construction (building walls or windows) to sports and leisure (boat sails or tents) or consumer electronics (watch straps and phone cases). As we recently argued1, LSC is a powerful photonic platform finding an ever-expanding range of applications beyond generating electricity, including in sensing, photochemistry, horticulture and even in optical communications.

In our group we research LSCs through a range of development stages:

Theory – We have explored the fundamental limits of LSC performance, investigating the thermodynamic principles of the technology2.

Simulation – Our group has developed a Monte-Carlo methods ray-tracing model which underpins many of our activities. The simulation platform allows us to predict, design and optimise LSC devices, creating novel designs.

Efficiency enhancement – In combination with our simulation platform we have proposed a range of enhancement techniques to push LSC efficiencies towards commercial viability. These techniques include dye alignment3, plasmonics4, Forster energy transfer 5, and wavelength selective mirrors6.

Fabrication – With our in-house fabrication facilities we put our ideas to practise with prototype devices, always considering the materials and techniques required for up-scaling and industrial commercialisation. For example, our studies into viable flexible LSCs can increase the range of possible applications and fabrication techniques 7,8. 

Characterisation – We have a range state-of-the-art fabrication techniques which allow us to characterise and assess the performance of our developed devices

LSCs used as receivers in high-speed visible light communications systems9 and LSCs used in horticulture to promote plant growth10.

LSCs used as receivers in high-speed visible light communications systems9 and LSCs used in horticulture to promote plant growth10.

Figure 3 – LSCs used as receivers in high-speed visible light communications systems9 and LSCs used in horticulture to promote plant growth10.

Our research is not limited to using LSCs solely for the purpose of solar collection. We believe the technology can be used in a cross-disciplinary manner and techniques can be transferred and extended to a range of applications including optical communications9, agriculture technology10 and medical sensing, Figure 3.

Representative publications

1. Papakonstantinou, I., Portnoi, M. & Debijie, M. G. The hidden potential of Luminescent Solar Concentrators. Adv. Energy Mater. Accept. Press 2002883, 1–13 (2020).

2. Papakonstantinou, I. & Tummeltshammer, C. Fundamental limits of concentration in luminescent solar concentrators revised: the effect of reabsorption and nonunity quantum yield. Optica (2015). doi:10.1364/optica.2.000841

3. Tummeltshammer, C., Taylor, A., Kenyon, A. J. & Papakonstantinou, I. Homeotropic alignment and Förster resonance energy transfer: The way to a brighter luminescent solar concentrator. J. Appl. Phys. 116, 173103 (2014).

4. Tummeltshammer, C., Brown, M. S., Taylor, A., Kenyon, A. J. & Papakonstantinou, I. Efficiency and loss mechanisms of plasmonic Luminescent Solar Concentrators. Opt. Express (2013). doi:10.1364/oe.21.00a735

5. Tummeltshammer, C. et al. On the ability of Förster resonance energy transfer to enhance luminescent solar concentrator efficiency. Nano Energy 32, 263–270 (2017).

6. Portnoi, M. et al. All-Silicone-based Distributed Bragg Reflectors for Efficient Flexible Luminescent Solar Concentrators. Nano Energy 70, 104507 (2020).

7. Portnoi, M., Sol, C., Tummeltshammer, C. & Papakonstantinou, I. Impact of curvature on the optimal configuration of flexible luminescent solar concentrators. Opt. Lett. (2017). doi:10.1364/ol.42.002695

8. Tummeltshammer, C., Taylor, A., Kenyon, A. J. & Papakonstantinou, I. Flexible and fluorophore-doped luminescent solar concentrators based on polydimethylsiloxane. Opt. Lett. (2016). doi:10.1364/ol.41.000713

9. Portnoi, M. et al. Bandwidth Limits of Luminescent Solar Concentrators as Detectors in Free-Space Optical Communication Systems. Light Sci. Appl. 10, (2021).

10. Xu, Z., Portnoi, M., Papakonstantinou, I., Micro-cone arrays enhance outcoupling efficiency in horticulture luminescent solar concentrators. arXiv preprint arXiv:2206.14766

 (2022).

Funding

  1. Chinese Scholarship Council PhD studentship (2021-2024).
  2. UCL BEAMS Dean’s Award (2021-2024).
  3. IntelGlazing, Intelligent functional coating with self-cleaning properties to improve the energy efficiency of the built environment. European Research Council, ERC-StG GA 679891 (2016-2022).
  4. MARVEL, Multifunctional Polymer Light-Emitting Diodes with Visible Light Communications. EPSRC, EP/P006280/1 (2016-2020).
  5. SOLAR-PLUS, Maximizing the efficiency of Luminescent Solar Concentrators by implanting resonant plasmonic nanostructures”, FP7 programme, Marie-Curie, Career Integration Grant, No. 293567 (2011-2015).