This review highlights recent developments in the grafting of conjugated polymers onto various substrates for organic electronic devices. The rapid development of multi-layer architectures demands ...the preparation of well-defined interfaces between both compatible and incompatible materials. It is promising therefore that interface-engineering is now known to help passivate charge trap states, control energy level alignments, enhance charge extraction, guide active-layer morphologies, and improve material compatibility, adhesion and device stability. In organic electronic devices, conjugated polymers are in contact with a wide range of constituents, such as metals, metal oxides, organic materials, and inorganic particles. Covalent bonds between these materials and macromolecules are desired to yield intimate contacts and well-defined interfaces. Following an overview of the various synthetic methodologies of conjugated polymers, the chemistry of tethering macromolecular chains onto nanoparticles and flat surfaces is described. The creation of functional hybrid materials offers the potential to deliver efficient and low-cost devices.
N‐phosphonomethyle‐glycine (glyphosate) is the most widely used pesticide worldwide due to its effectiveness in killing weeds at a moderate cost, bringing significant economic benefits. However, ...owing to its massive use, glyphosate and its residues contaminate surface waters. On site, fast monitoring of contamination is therefore urgently needed to alert local authorities and raise population awareness. Here the hindrance of the activity of two enzymes, the exonuclease I (Exo I) and the T5 exonuclease (T5 Exo) by glyphosate, is reported. These two enzymes digest oligonucleotides into shorter sequences, down to single nucleotides. The presence of glyphosate in the reaction medium hampers the activity of both enzymes, slowing down enzymatic digestion. It is shown by fluorescence spectroscopy that the inhibition of ExoI enzymatic activity is specific to glyphosate, paving the way for the development of a biosensor to detect this pollutant in drinking water at suitable detection limits, i.e., 0.6 nm.
Glyphosate hinders the enzymatic activity of exonucleases, paving the way for the future development of a biosensor to detect this pollutant.
Here efficient organic photovoltaic devices fabricated from water‐based colloidal dispersions with donor:acceptor composite nanoparticles achieving up to 9.98% power conversion efficiency (PCE) are ...reported. This high efficiency for water processed organic solar cells is attributed to morphology control by surface energy matching between the donor and the acceptor materials. Indeed, due to a low interfacial energy between donor and the acceptor, no large phase separation occurs during the nanoparticle formation process as well as upon thermal annealing. Indeed, synchrotron‐based scanning transmission X‐ray microscopy reveals that the internal morphology of composite nanoparticles is intermixed as well as the active layer morphology after thermal treatment. The PCE of this system reaches 85% that of devices prepared from chlorinated solvent. The gap between water‐based inks and organic solvent‐based inks gets narrower, which is promising for the development of eco‐friendly processing and fabrication of organic photovoltaics.
This article describes the fabrication of organic photovoltaic devices from water‐based nanoparticle dispersions. By careful control of the surface energies, optimal nanoparticle morphology is achieved, leading to devices with up to 9.98% power conversion efficiency. This study opens the route for environmentally friendly processes for organic photovoltaics.
The functionalization of zinc oxide (ZnO) nanoparticles by poly(3‐hexylthiophene) (P3HT) brush is completed by the combination of a mussel inspired biomimetic anchoring group and Huisgen ...cyclo‐addition “click chemistry.” Herein, the direct coupling of an azide modified catechol derivative with an alkyne end‐functionalized P3HT is described. This macromolecular binding agent is used to access core@corona ZnO@P3HT with a stable and homogeneous conjugated organic corona. Preliminary photoluminescence measurement proves an efficient electron transfer from the donor P3HT to the acceptor ZnO nanoparticles upon grafting, thus demonstrating the potential of such a combination in organic electronics.
The functionalization of zinc oxide (ZnO) nanoparticles by poly(3‐hexylthiophene) (P3HT) brush is completed by the combination of a mussel inspired biomimetic anchoring group and Huisgen cyclo‐addition “click chemistry.” Photoluminescence measurement proves an efficient electron transfer from the donor P3HT to the acceptor ZnO nanoparticles.
Development of carbon neutral and sustainable energy sources should be considered as a top priority solution for the growing worldwide energy demand. Photovoltaics are a strong candidate, more ...specifically, organic photovoltaics (OPV), enabling the design of flexible, lightweight, semitransparent, and low-cost solar cells. However, the active layer of OPV is, for now, mainly deposited from chlorinated solvents, harmful for the environment and for human health. Active layers processed from health and environmentally friendly solvents have over recent years formed a key focus topic of research, with the creation of aqueous dispersions of conjugated polymer nanoparticles arising. These nanoparticles are formed from organic semiconductors (molecules and macromolecules) initially designed for organic solvents. The topic of nanoparticle OPV has gradually garnered more attention, up to a point where in 2018 it was identified as a “trendsetting strategy” by leaders in the international OPV research community. Hence, this review has been prepared to provide a timely roadmap of the formation and application of aqueous nanoparticle dispersions of active layer components for OPV. We provide a thorough synopsis of recent developments in both nanoprecipitation and miniemulsion for preparing photovoltaic inks, facilitating readers in acquiring a deep understanding of the crucial synthesis parameters affecting particle size, colloidal concentration, ink stability, and more. This review also showcases the experimental levers for identifying and optimizing the internal donor–acceptor morphology of the nanoparticles, featuring cutting-edge X-ray spectromicroscopy measurements reported over the past decade. The different strategies to improve the incorporation of these inks into OPV devices and to increase their efficiency (to the current record of 7.5%) are reported, in addition to critical design choices of surfactant type and the advantages of single-component vs binary nanoparticle populations. The review naturally culminates by presenting the upscaling strategies in practice for this environmentally friendly and safer production of solar cells.
A series of novel block copolymers, processable from single organic solvents and subsequently rendered amphiphilic by thermolysis, have been synthesized using Grignard metathesis (GRIM) and ...reversible addition–fragmentation chain transfer (RAFT) polymerizations and azide–alkyne click chemistry. This chemistry is simple and allows the fabrication of well-defined block copolymers with controllable block lengths. The block copolymers, designed for use as interfacial adhesive layers in organic photovoltaics to enhance contact between the photoactive and hole transport layers, comprise printable poly(3-hexylthiophene)-block-poly(neopentyl p-styrenesulfonate), P3HT-b-PNSS. Subsequently, they are converted to P3HT-b-poly(p-styrenesulfonate), P3HT-b-PSS, following deposition and thermal treatment at 150 °C. Grazing incidence small- and wide-angle X-ray scattering (GISAXS/GIWAXS) revealed that thin films of the amphiphilic block copolymers comprise lamellar nanodomains of P3HT crystallites that can be pushed further apart by increasing the PSS block lengths. The approach of using a thermally modifiable block allows deposition of this copolymer from a single organic solvent and subsequent conversion to an amphiphilic layer by nonchemical means, particularly attractive to large scale roll-to-roll industrial printing processes.
In Situ Generation of Fullerene from a Poly(fullerene) Silva, Hugo Santos; Ramanitra, Hasina H.; Bregadiolli, Bruna A. ...
Journal of polymer science. Part B, Polymer physics,
November 1, 2019, Letnik:
57, Številka:
21
Journal Article
A series of poly(3‐hexylthiophene)s (P3HTs) and poly(3‐butylthiophene)s (P3BTs) with predetermined molecular weights and varying polydispersities are prepared using a simplified Grignard metathesis ...chain‐growth polymerization. Techniques were elaborated to prepare extremely high molecular weight P3HT (number‐average molecular weight of around 280 000 g mol–1) with a low polydispersity (< 1.1) without resorting to fractionation. Optimization of the annealing of a series of solar cells based on blends of poly(3‐alkylthiophene)s (P3ATs) and 6,6‐phenyl C61 butyric acid methyl ester indicates that the polydispersities, molecular weights, and degrees of conjugation of the P3ATs all have an important impact not only on cell characteristics but also on the most effective annealing temperature required. The results indicate that each cell requires annealing treatments specific to the type of polymer and its molecular weight distribution.
A modified chain‐growth polymerization directly yields high‐molecular‐weight poly(3‐hexylthiophene) of tentative Mn≈280 000 g mol–1 (number‐average value), and polydispersity <1.1. Optimization of bulk‐heterojunction photovoltaic cells (see figure) using such poly(3‐hexythiophene)s or poly(3‐butylthiophene)s and 6,6‐phenyl C61 butyric acid methyl ester is found to depend on overall molecular weight distributions.
The recent interest in the application of organic semiconductor colloids to photocatalytic hydrogen evolution has sparked the need for an assessment of the current state of this research field. Here, ...we showcase how the lessons learned from organic photovoltaics (OPV) research can be applied to new applications in the generation of solar fuels, such as in photocatalytic hydrogen evolution. Photovoltaics generated from organic semiconductor nanoparticles (NPs) started with a power conversion efficiency at less than 0.01% in 2003, since then the technology witnessed a steady climb to 7.5% reported in 2018. A large fraction of this technology improvement can be attributed to morphology improvement of the organic semiconductor colloids, improvements which can now be transferred to benefit the field of photocatalytic hydrogen evolution. We begin with an introduction to conjugated materials, then move to a thorough description of NP dispersion processes, comprising the miniemulsion and the nanoprecipitation methods, before moving to a summary of the different morphologies encountered in organic NPs, their impact on OPV performance and how this parameter is of crucial importance for photocatalytic hydrogen generation. Indeed, organic semiconductor colloids conveniently provide the field of photocatalytic hydrogen generation with a nanoengineering toolkit upon which to customize morphologies to increase photocatalytic activity and enhance hydrogen evolution rates (HER).
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