The Hidden Potential of Luminescent Solar Concentrators

The luminescent solar concentrator (LSC), originally introduced almost four decades ago as a potential alternative/complement to silicon solar cells, has since evolved to a versatile photovoltaic (PV) solution with realistic potential for seamless integration into the urban architectural landscape. Yet, a popular perception of the device still persists: the LSC is mostly seen as just a low‐efficiency solar panel. This review challenges this outdated notion and argues that the LSC is, to the contrary, a powerful and highly adaptive photonic platform with many more capabilities and potential than only generating electricity from sunlight. The field has seen a rapidly expanding application portfolio over the last few years, with LSCs now considered in various sensing applications, “smart” windows, chemical reactors, horticulture, and even in optical communication and real‐time responsive systems. The main goal of this work is to shed light onto this alternative application space and highlight the LSC's unique spectral manipulation, light distribution, and light concentration properties, and as a result, to encourage the participation from a broader range of disciplines into LSC research with the ultimate aim of stimulating the development of novel, LSC inspired technologies

Monodisperse Liquid Crystal Network Particles Synthesized via Precipitation Polymerization

The production of liquid crystalline (LC) polymer particles with a narrow size distribution on a large scale remains a challenge. Here, we report the preparation of monodisperse, cross-linked liquid crystalline particles via precipitation polymerization. This versatile and scalable method yields polymer particles with a smectic liquid crystal order. Although the LC monomers are randomly dissolved in solution, the oligomers self-align and LC order is induced. For the polymerization, a smectic LC monomer mixture consisting of cross-linkers and benzoic acid hydrogen-bonded dimers is used. The average diameter of the particles increases at higher polymerization temperatures and in better solvents, whereas the monomer and initiator concentration have only minor impact on the particle size. After deprotonating of the benzoic acid groups, the particles show rapid absorption of a common cationic dye, methylene blue. The methylene blue in the particles can be subsequently released with the addition of Ca2+, while monovalent ions fail to trigger the release. These results reveal that precipitation polymerization is an attractive method to prepare functional LC polymer particles of a narrow size distribution and on a large scale

Nanohybrid Materials with Tunable Birefringence via Cation Exchange in Polymer Films

In this work, a nanohybrid material based on a freestanding polymeric liquid crystal network capable of postmodification via cation exchange to tune birefringence is proposed. The smectic liquid crystal films can be infiltrated with a variety of cations, thereby changing the refractive indices (ne and no) and the effective birefringence (Δn) of the nanohybrid material, with reversible cation infiltration occurring within minutes. Birefringence could be tuned between values of 0.06 and 0.19, depending on the cation infiltrated into the network. Upon infiltration, a decrease in the smectic layer spacing is found with layer contraction independent of the induced change in birefringence. Potential applications are in the field of specialty optical devices, such as flexible, retunable reflective filters

Status report on emerging photovoltaics

\ua9 2023 Society of Photo-Optical Instrumentation Engineers (SPIE).This report provides a snapshot of emerging photovoltaic (PV) technologies. It consists of concise contributions from experts in a wide range of fields including silicon, thin film, III-V, perovskite, organic, and dye-sensitized PVs. Strategies for exceeding the detailed balance limit and for light managing are presented, followed by a section detailing key applications and commercialization pathways. A section on sustainability then discusses the need for minimization of the environmental footprint in PV manufacturing and recycling. The report concludes with a perspective based on broad survey questions presented to the contributing authors regarding the needs and future evolution of PV

Radiation chemistry of solid-state carbohydrates using EMR

We review our research of the past decade towards identification of radiation-induced radicals in solid state sugars and sugar phosphates. Detailed models of the radical structures are obtained by combining EPR and ENDOR experiments with DFT calculations of g and proton HF tensors, with agreement in their anisotropy serving as most important criterion. Symmetry-related and Schonland ambiguities, which may hamper such identification, are reviewed. Thermally induced transformations of initial radiation damage into more stable radicals can also be monitored in the EPR (and ENDOR) experiments and in principle provide information on stable radical formation mechanisms. Thermal annealing experi-ments reveal, however, that radical recombination and/or diamagnetic radiation damage is also quite important. Analysis strategies are illustrated with research on sucrose. Results on dipotassium glucose-1-phosphate and trehalose dihydrate, fructose and sorbose are also briefly discussed. Our study demonstrates that radiation damage is strongly regio-selective and that certain general principles govern the stable radical formation

Renewable energy : better luminescent solar panels in prospect

Devices known as luminescent solar concentrators could find use as renewable-energy generators, but have so far been plagued by a major light-reabsorption effect. A new study offers a promising route to tackling this proble

Implementing a practical, bachelor’s-level design-based learning course to improve chemistry students’ scientific dissemination skills

\u3cp\u3eThis work presents an outline for a full-quartile design-based learning laboratory-based course suitable for final year Bachelor's students. The course has been run for 5 years in the department of Chemical Engineering and Chemistry. The course attempts to provide a complete laboratory experience for its students, including an authentic research project, experience in writing a research paper with realistic limitations of both space and time, and giving of a presentation appropriate for a scientific conference, finally culminating with a written exam, where the questions are based on the written reports and oral presentations of the other students, making the students also course teachers . This article will discuss both the successful aspects of the course and point out the areas that still need improvement and provides enough information as to allow the transfer of the methodology to other educational curricula.\u3c/p\u3

Progress in luminescent solar concentrator research: solar energy for the built environment

This paper presents a concise review of recent research on the luminescent solar concentrator (LSC). The topics covered will include studies of novel luminophores and attempts to limit the losses in the devices, both surface and internal. These efforts include application of organic and inorganic-based selective mirrors which allow sunlight in but reflect emitted light, luminophores alignment to manipulate the emitted light path, and patterning of the dye layer. Finally, the paper will offer some possible ‘glimpses to the future’, and offer some additional research paths that could result in a device that could make solar energy a ubiquitous part of the built environment as sound barriers, bus stop roofs, awnings or siding tiles. Considering the reported efficiencies of the LSC are comparable to those reported for organic PVs, which are also being considered for use in the built environment, the results of the research on the LSC to date warrants more widespread attention

Reduction of escape cone losses in luminescent solar concentrators with cholesteric mirrors

The Luminescent Solar Concentrator (LSC) consists of a transparent polymer plate containing luminescent particles. Solar cells are connected to one or more sides of the polymer plate. Part of the light emitted by the luminescent particles\u3cbr/\u3eis guided towards the solar cells by total internal reflection. About 25% of the dye emission is typically emitted within the optical escape cone of the matrix material and is lost due to emission from the top. We study the application of selectively-reflective cholesteric layers to reduce these losses. We have implemented these mirrors in the ray-tracing model for the LSC. The simulations show that an optimum in performance can be obtained by selecting an appropriate centre wavelength of the cholesteric mirror.\u3cbr/\u3eExternal Quantum Efficiency measurements were performed on LSC devices with a mc-Si, GaAs or InGaP cell and a dichroic mirror. This mirror shows a similar behavior as the cholesteric mirror. The results show that for a 5x5 cm2 LSC\u3cbr/\u3ethe mirror does improve the EQE in the absorption range of the dye