Orange/Red Benzo[1,2-b:4,5-b']dithiophene 1,1,5,5-Tetraoxide-Based Emitters for Luminescent Solar Concentrators: Effect of Structures on Fluorescence Properties and Device Performances

Recent developments in polymer chemistry, medicinal chemistry and electro-optics using Ni and Pd-based catalytic systems

Catalysis is the fastest and continuously growing field in chemistry. A key component of this process is catalytic systems, which result in increased reaction rates and yields, as well as the ability to tailor the properties of products to the final application. With the development of catalysis, the requirements for catalysts used in these processes have also grown rapidly. Modern catalytic materials should overcome the challenges posed by the modern world of chemistry. They should be durable, and stable, have good catalytic properties, and allow catalytic processes to be carried out under mild and environmentally friendly conditions. In this article, we provide an overview of recent reports on the use of catalytic systems based on nickel and palladium ions in catalytic reactions, leading to functional materials used in the fields of medicinal chemistry, polymer chemistry and electro-optical materials chemistry. Research on the optimization and modification of existing synthetic methods, reports on the synthesis of new functional materials, and articles on new, more efficient catalytic systems that overcome the drawbacks of existing catalysts are described. The presented article reviews current knowledge, providing the newest information from the world of catalysis and synthesis of advanced functional materials, presenting potential directions for further development in these fields.

Poly(styrene sulfonate-co-glycidyl methacrylate)/Rhodamine B Films with Enhanced Energy Conversion in Luminescent Solar Concentrators Triggered by Aromatic-Aromatic Interactions

Styrene sulfonate-glycidyl methacrylate copolymers have been rationally designed to furnish both insolubility in water and negatively charged aromatic functional groups that, upon undergoing aromatic-aromatic interactions with dyes, impart specific functionality to solid materials. Solid films incorporating varying amounts of the embedded fluorophore rhodamine B were obtained by solution casting of the copolymers onto glass substrates. The formed slabs were then evaluated for their potential use in energy conversion devices such as luminescent solar concentrators. The materials presented higher dye dispersion, avoiding nonfluorescent aggregates, increased fluorescence emission intensity, larger Stokes shift, lower absorption and emission overlap, reduced reabsorption, and longer fluorescence lifetime, compared with matrices made of rhodamine B/poly(methyl methacrylate). The higher dispersion, polarity, and charge transfer character in the excited state are claimed as the cause of these photophysical properties produced by the functional polymers. Tested in luminescent solar concentrator devices of 50 × 50 × 4 mm3, the device efficiency obtained reached 1.19%, whereas control devices made with rhodamine B/poly(methyl methacrylate) matrices only reached 0.33%. This aims at functional polymers containing aromatic charged residues in the solid state as potential tools to achieve improved performance in energy conversion devices based on the modulation of the photophysical response of aromatic dyes by means of aromatic-aromatic interactions.

Aggregation-induced emissive nanoarchitectures for luminescent solar concentrators

Aggregation-induced emission (AIE), the phenomenon by which selected luminophores undergo the enhancement of emission intensity upon aggregation, has demonstrated potential in materials and biomaterials science, and in particular in those branches for which spectral management in the solid state is of fundamental importance. Its development in the area of luminescent spectral conversion devices like luminescent solar concentrators (LSCs) is instead still in its infancy. This account aims at summarizing relevant contributions made in this field so far, with a special emphasis on the design of molecular and macromolecular architectures capable of extending their spectral breadth to the deep-red (DR) and the near-infrared (NIR) wavelengths. Because of the many prospective advantages characterizing these spectral regions in terms of photon flux density and human-eye perception, it is anticipated that further development in the design, synthesis and engineering of advanced molecular and macromolecular DR/NIR-active AIE luminophores will enable faster and easier integration of LSCs into the built environment as highly transparent, active elements for unobtrusive light-to-electricity conversion.

Semi-Transparent Luminescent Solar Concentrators Based on Intramolecular Energy Transfer in Polyurethane Matrices

Luminescent solar concentrators (LSCs) are spectral conversion devices offering interesting opportunities for the integration of photovoltaics into the built environment and portable systems. The Förster-resonance energy transfer (FRET) process can boost the optical response of LSCs by reducing energy losses typically associated to non-radiative processes occurring within the device under operation. In this work, a new class of FRET-based thin-film LSC devices is presented, in which the synthetic versatility of linear polyurethanes (PU) is exploited to control the photophysical properties and the device performance of the resulting LSCs. A series of luminescent linear PUs are synthesized in the presence of two novel bis-hydroxyl-functionalized luminophores of suitable optical properties, used as chain extenders during the step-growth polyaddition reaction for the formation of the linear macromolecular network. By synthetically tuning their composition, the obtained luminescent PUs can achieve a high energy transfer efficiency (≈90%) between the covalently linked luminophores. The corresponding LSC devices exhibit excellent photonic response, with external and internal photon efficiencies as high as ≈4% and ≈37%, respectively. Furthermore, their optimized power conversion efficiency combined with their enhanced average visible-light transmittance highlight their suitability for potential use as transparent solar energy devices.

A comprehensive dataset of photonic features on spectral converters for energy harvesting

Building integrated photovoltaics is a promising strategy for solar technology, in which luminescent solar concentrators (LSCs) stand out. Challenges include the development of materials for sunlight harvesting and conversion, which is an iterative optimization process with several steps: synthesis, processing, and structural and optical characterizations before considering the energy generation figures of merit that requires a prototype fabrication. Thus, simulation models provide a valuable, cost-effective, and time-efficient alternative to experimental implementations, enabling researchers to gain valuable insights for informed decisions. We conducted a literature review on LSCs over the past 47 years from the Web of ScienceTM Core Collection, including published research conducted by our research group, to gather the optical features and identify the material classes that contribute to the performance. The dataset can be further expanded systematically offering a valuable resource for decision-making tools for device design without extensive experimental measurements.

Effect of Polymer Composition on the Optical Properties of a New Aggregation-Induced Emission Fluorophore: A Combined Experimental and Computational Approach

Nowadays, fluorophores with a tetraphenylethylene (TPE) core are considered interesting due to the aggregation-induced emission (AIE) behavior that enables their effective use in polymer films. We propose a novel TPE fluorophore (TPE-BPAN) bearing two dimethylamino push and a 4-biphenylacetonitrile pull moieties with the typical AIE characteristics in solution and in the solid state, as rationalized by DFT calculations. Five different host polymer matrices with different polarity have been selected: two homopolymers of poly(methylmethacrylate) (PMMA) and poly(cyclohexyl methacrylate) (PCHMA) and three copolymers at different compositions (P(MMA-co-CHMA) 75:25, 50:50, and 25:75 mol%). The less polar comonomer of CHMA appeared to enhance TPE-BPAN emission with the highest quantum yield (QY) of about 40% measured in P(MMA-co-CHMA) 75:25. Further reduction in polymer polarity lowered QY and decreased the film stability and adhesion to the glass surface. LSC performances were not significantly affected by the matrix's polarity and resulted in around one-third of the state-of-the-art due to the reduced QY of TPE-BPAN. The theoretical investigation based on density functional theory (DFT) calculations clarified the origin of the observed AIE and the role played by the environment in modulating the photophysical behavior.