Quantum Dot–Block Copolymer Hybrids for Low Scattering Luminescent Solar Concentrators

Abstract

Luminescent solar concentrators (LSCs) use down-converting phosphors embedded in a transparent waveguide to absorb sunlight, trap luminescent photons by total internal reflection, and deliver high irradiance, narrowband output light for driving photovoltaic, photochemical, and other solar energy converters. Quantum-dot-based (QD) LSCs are typically affected by several optical loss mechanisms including the loss of a fraction of guided light during transport to the concentrator edges through scattering from QD aggregates. Although the recent introduction of large effective Stokes shift QD luminophores for LSC applications has helped address several shortcomings associated with previous generations of organic and inorganic dyes, including improved solar spectrum matching, photostability, and photoluminescence quantum yield, achieving low light scattering at technologically relevant QD loadings in commercially deployed polymers such as poly­(methyl methacrylate) (PMMA) remains challenging. Herein, we study the concept of applying QDs bearing polymer ligands matching the composition of the LSC matrix to reduce aggregation and the resulting parasitic waveguide losses caused by scattering. We report the synthesis and characterization of a thiol-terminated PMMA-based ligand and its successful ligand exchange reaction with copper indium disulfide/zinc sulfide (CIS/ZnS) QDs. QDs bearing PMMA ligands are then applied as down-converting phosphors embedded in a PMMA waveguide. The resulting QD-based LSCs were found to have lower optical scattering with higher loading as a result of reduced aggregation in the devices.

Strategies for the optimization of color neutral, transparent, and efficient luminescent solar concentrators

“…Polymers designed to cap QDs have been shown to increase the solubility of the particles and reduce their aggregation. 92 Durable materials under working conditions are essential to keep performing in the long term. The waveguide material needs to withstand mechanical impacts, sunlight exposition, and temperature and humidity while preventing the degradation of the luminophore.…”

Multishell Silver Indium Selenide-Based Quantum Dots and Their Poly(methyl methacrylate) Composites for Application in Red-Light-Emitting Diodes

“…The large interest in the application of QDs in photonic devices has stimulated several researchers to investigate their incorporation in polymeric matrixes for the production of multiple devices, including luminescence solar concentrators, − scintillators, and color conversion layers for (LEDs). , In particular, bulk radical polymerization is of high interest for its versatility and potential industrial application . However, the harsh reaction conditions are often incompatible with the presence of the nanoparticles, and a significant reduction in the QD photoluminescence is commonly related to the reaction with radicals and combined with a poor homogeneity of the composite due to phase separation. − A large focus on in situ polymerization in the presence of nanoparticles has been dedicated to Cd-based QDs and ZnS nanoparticles in poly­(methyl methacrylate) (PMMA) or octadecyl- p -vinyl benzyl dimethyl ammonium chloride (OVDAC). ,,, Only recently, the incorporation of ternary I–III–VI QDs has been reported; in particular, Dhamo et al investigated the incorporation of core/shell silver indium sulfide/ZnS QDs in the polylauroyl methacrylate matrix produced by photopolymerization under UV light.…”

“…However, the harsh reaction conditions are often incompatible with the presence of the nanoparticles, and a significant reduction in the QD photoluminescence is commonly related to the reaction with radicals and combined with a poor homogeneity of the composite due to phase separation. − A large focus on in situ polymerization in the presence of nanoparticles has been dedicated to Cd-based QDs and ZnS nanoparticles in poly­(methyl methacrylate) (PMMA) or octadecyl- p -vinyl benzyl dimethyl ammonium chloride (OVDAC). ,,, Only recently, the incorporation of ternary I–III–VI QDs has been reported; in particular, Dhamo et al investigated the incorporation of core/shell silver indium sulfide/ZnS QDs in the polylauroyl methacrylate matrix produced by photopolymerization under UV light. Similarly, Koch et al used copper indium sulfide/ZnS QDs coated with the polymeric ligand to produce a PMMA composite via polymerization of a PMMA/MMA mixture.…”

Grafting of Poly(methyl methacrylate) with Different Sulfur-Containing End Groups on Gold Nanoparticles and Their Interfacial Assembly into Superlattice Films

“…14 This method could also be applied to other homopolymers (i.e., poly(N-isopropylacrylamide), 15 poly(acrylic acid), 16 etc.) and block copolymers (i.e., poly(2-(2-methoxyethoxy)ethyl methacrylate)-b-PS, 17 PMMA-b-PS, 18 etc. ).…”