Highly emissive fluorescent silica-based core/shell nanoparticles for efficient and stable luminescent solar concentrators

Abstract

Luminescent solar concentrators (LSCs) represent a viable spectral conversion technology to maximize sunlight harvesting while promising to reduce the current gap for integration of solar cells into the built environment. In this work, novel highly emissive and photostable core-shell nanostructured luminescent species were synthesized and used in LSC devices. Such systems were obtained by entrapping Lumogen F Red 305 in silica-based shells by means of the sol-gel process using a combination of hydrophilic (tetraethyl orthosilicate) and hydrophobic (phenyl triethoxysilane) silica precursors. By tuning their relative proportions during the synthetic process, fine control over the characteristic dimensions and morphology of the obtained dye-doped core-shell nanoparticles could be achieved, leading to a maximum concentration of non-covalently entrapped fluorescent dye of ~1 wt.%. Optical characterization showed that the newly synthetized nanoparticles displayed markedly improved photoluminescence quantum yield in solid state (~ 95 %) with respect to the non-encapsulated dye (~ 2 %), as a result of an effective suppression of dye aggregation and fluorescence quenching phenomena. In addition, their excellent photostability under harsh UV light exposure was demonstrated, resulting from the protective action of the encapsulating hybrid silica-based shell, which can effectively limit photobleaching of the luminescent core. Their incorporation in thin-film LSCs led to a maximum internal photon efficiency as high as ~29%, thus providing evidence of their suitability as highly performing luminescent species with superior optical response and excellent photostability. Also, a maximum external photon efficiency as high as 2.12% was achieved. This work provides the first demonstration of silica-based encapsulation of Lumogen F Red 305 and of the application of silica-based core-shell nanoparticles in LSCs, thus paving the path to the development of a new class of highly efficient and stable nanostructured luminophores for the photovoltaic field.

Perylene Tetracarboxylic Acid Crosslinked to Silica Matrix that Enables Ultrahigh Solid‐State Quantum Yield and Efficient Photon Recycling for Holographic Luminescent Solar Concentrators

“…For example, Corsini et al demonstrated highly emissive nanoparticles based on Lumogen F Red 305 with thick silica‐based shells, which exhibited ultrahigh solid‐state QYs of 95% (relative to nonshelled dyes with only 2%) and stable emission. [ 41 ] Thin‐film LSCs with the lateral area of 25 cm 2 were prepared by coating the mixtures of those nanoparticles (in the powdered form) and PDMS polymer with various loading concentrations on the glass waveguides. The PCE values between 0.5% and 1.07% were obtained for their LSCs with different loadings.…”

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

“…Beyond that value, η opt decreased. This trend is common in LSC characterization and can be addressed by two counteracting effects caused by the growing content of the fluorophore in the thin films: the light-harvesting efficiency rises as an increased amount of dye molecules in the LSC system can absorb a larger fraction of light; the probability of reabsorption of photons within the LSC film increases because of the larger overlap between absorption and emission spectra, while the fluorescence quantum yield diminishes [51]. In addition, the increased concentration may lead to the formation of less emissive supramolecular aggregates (aggregation-induced quenching phenomena) [52,53].…”

Review on Colloidal Quantum Dots Luminescent Solar Concentrators

“…The performance of an LSC is heavily determined by the optical characteristics of the luminophore and its concentration in the LSC. Much attention has been given to QDs as ideal luminophores for their wide absorption spectra, controllable emission spectra, and high stability [24–30] . In addition to applications in LSC technology, the controllable emissions spectra of QDs have enabled the development of QDs as a photocatalyst in hydrogen production [31–36] .…”