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Conjugated polymers are promising photoactive materials for heterogeneous photocatalysis, but their limited solubility hinders the scalability in practical use. Herein, we develop polymer composites using processable conjugated polyelectrolytes and ionomers to fabricate photocatalytic thin films with visible light activity. The composite of conjugated polyelectrolytes and ionomers with identical counter anions in their side chains enables compatibility in solvents and stabilized charged states within the composite. This facilitates the development of stable coatings on diverse substrates and enhances charge separation and transport. The resulting photocatalytic thin films exhibited a 1.5‐fold increase in photocurrent response and a 7.0‐fold increase in mechanical strength compared to the pristine conjugated polymer. Photoactive coatings with polymer composites showcase the potential for synergistic photocatalytic oxidation of NADH, organic dye, and sulfide under visible light irradiation. The photocatalytic thin films are stable, versatile, and scalable for various photocatalytic reactions, showing promise for developing upscaled photoreactors. [ABSTRACT FROM AUTHOR]

Artificial light harvesting, a process that involves converting sunlight into chemical potential energy, is considered to be a promising part of the overall solution to address urgent global energy challenges. Conjugated polyelectrolyte complexes (CPECs) are particularly attractive for this purpose due to their extended electronic states, tunable assembly thermodynamics, and sensitivity to their local environment. Importantly, ionically assembled complexes of conjugated polyelectrolytes can act as efficient donor-acceptor pairs for electronic energy transfer (EET). However, to be of use in material applications, we must understand how modifying the chemical structure of the CPE backbone alters the EET rate beyond spectral overlap considerations. In this report we investigate the dependence of the EET efficiency and rate on the electronic structure and excitonic wave function of the CPE backbone. To do so, we synthesized a series of alternating copolymers where the electronic states are systematically altered by introducing comonomers with electron withdrawing and electron-rich character while keeping the linear ionic charge density nearly fixed. We find evidence that the excitonic coupling may be significantly affected by the exciton delocalization radius, in accordance with analytical models based on the line-dipole approximation and quantum chemistry calculations. Our results imply that care should be taken when selecting CPE components for optimal CPEC EET. These results have implications for using CPECs as key components in water-based light-harvesting materials, either as standalone assemblies or as adsorbates on nanoparticles and thin films.

Multidrug resistance to clinical chemotherapeutic drugs severely limits antitumor efficacy and patient survival. The integration of chemotherapy with photothermal therapy (PTT) and reactive nitrogen species has become a major strategy to enhance cancer treatment efficacy. Herein, a multifunctional peroxynitrite (ONOO−) nanogenerator (PBT/NO/Pt) for NIR‐II fluorescence (NIR‐II FL)/NIR‐II photoacoustic (NIR‐II PA) imaging‐guided chemo/NIR‐II PTT/ONOO− combination therapy is reported. The multifunction nanogenerator is developed by co‐loading a pH‐sensitive nitric oxide donor (DETA NONOate) and nicotinamide adenine dinucleotide phosphate oxidases trigger superoxide (O2•−) generator chemotherapy drug (CDDP) to an NIR‐II excitation‐conjugated polyelectrolyte (PNC11BA). PNC11BA has non‐conjugated alkyl chain segments in the polymer backbone and abundant positively charged phenylboronic acid in its side chains, which support the anti‐quenching of NIR‐II FL and the integration of DETA NONOate and CDDP into PBT/NO/Pt. In the acidic tumor microenvironment, the coordination bonds between CDDP and PNC11BA are cleaved, releasing CDDP for chemotherapeutic activity. The simultaneous release of nitric oxide (NO) and O2•− rapidly leads to the in situ generation of the more cytotoxic reactive physiological nitrogen species ONOO−. In vitro and in vivo results prove that PBT/NO/Pt exhibited a markedly ONOO− enhanced chemo–photothermal synergistic therapy for SKOV3/DDP tumor by downregulating the intracellular glutathione and increasing CDDP–DNA adducts. [ABSTRACT FROM AUTHOR]

Three sulfonate‐containing polyelectrolytes are elaborately designed and used to passivate perovskite film with the anti‐solvent method. Under the influence of the secondary monomer, three copolymers present various chemical configurations and deliver different modification effects. Fluorene‐thiophene copolymer STF has linear and highly‐conjugated chain. STF‐perovskite film presents large crystal grains. Fluorene‐carbazole copolymer SCF has flexible chain and easily enters into grain boundary areas. SCF‐perovskite film is homogenous and continuous. Fluorene‐fluorene copolymer SPF agglomerates on the surface and is not applicable to the anti‐solvent method. The full investigation demonstrates that STF and SCF not only conduct surface defect passivation, but also improve the film quality by being involved in the perovskite's crystallization process. Compared with the control device, the devices with STF and SCF deliver high efficiency and excellent stability. The unencapsulated devices with STF and SCT maintain ≈80% of the initial power conversion efficiency (PCE) after 40 days of storage under 30–40% relative humidity. SCF performs better and the device maintains 60% of the initial PCE after 20 days of storage under 60–80% relative humidity. [ABSTRACT FROM AUTHOR]

Three new ionic polythiophene derivatives, soluble in polar solvents, are synthesized with good yields using simple, low‐cost, and straightforward procedures. They are investigated as interfacial cationic conjugated polyelectrolyte (CPE) layers for halogen‐free bulk heterojunction polymeric solar cells, based on a water‐soluble electron‐donor polymer (poly[3‐(6‐diethanolaminohexyl)thiophene]) and a water‐soluble electron‐acceptor fullerene derivative (malonodiserinolamide fullerene). The simple insertion of the CPE interlayer between the active layer and the aluminum cathode dramatically increases the power conversion efficiency of the final device up to nearly 5%, resulting from a decrease of the electrode work function, improved electron extraction, and optimization of the morphology of the layers. The obtained results demonstrate that the incorporation of CPE layer is a powerful and convenient methodology for the development of highly efficient and eco‐friendly processable polymeric solar cells. [ABSTRACT FROM AUTHOR]

High open-circuit voltage in Sb2Se3 thin-film solar cells is a key challenge in the development of earth-abundant photovoltaic devices. CdS selective layers have been used as the standard electron contact in this technology. Long-term scalability issues due to cadmium toxicity and environmental impact are of great concern. In this study, we propose a ZnO-based buffer layer with a polymer-film-modified top interface to replace CdS in Sb2Se3 photovoltaic devices. The branched polyethylenimine layer at the ZnO and transparent electrode interface enhanced the performance of Sb2Se3 solar cells. An important increase in open-circuit voltage from 243 mV to 344 mV and a maximum efficiency of 2.4% was achieved. This study attempts to establish a relation between the use of conjugated polyelectrolyte thin films in chalcogenide photovoltaics and the resulting device improvements. [ABSTRACT FROM AUTHOR]

Environmentally-benign materials play a pivotal role in advancing the scalability of energy storage devices. In particular, conjugated polymers constitute a potentially greener alternative to inorganic- and carbon-based materials. One challenge to wider implementation is the scarcity of n-doped conducting polymers to achieve full cells with high-rate performance. Herein, this work demonstrates the use of a self-doped n-doped conjugated polymer, namely poly(benzodifurandione) (PBDF), for fabricating aqueous supercapacitors. PBDF demonstrates a specific capacitance of 202 ± 3 F g -1 , retaining 81% of the initial performance over 5000 cycles at 10 A g -1 in 2 m NaCl ( aq ) . PBDF demonstrates rate performances of up to 100 and 50 A g -1 at 1 and 2 mg cm -2 , respectively. Electrochemical impedance analysis reveals a surface-mediated charge storage mechanism. Improvements can be achieved by adding reduced graphene oxide (rGO), thereby obtaining a specific capacitance of 288 ± 8 F g -1 and high-rate operation (270 A g -1 ). The performance of PBDF is examined in symmetric and asymmetric membrane-less cells, demonstrating high-rate performance, while retaining 83% of the initial capacitance after 100 000 cycles at 10 A g -1 . PBDF thus offers new prospects for energy storage applications, showcasing both desirable performance and stability without the need for additives or binders and relying on environmentally friendly solutions., (© 2024 Wiley‐VCH GmbH.)

[Display omitted] • A conjugated polyelectrolyte, PhH-1T, was adopted as a chemical dopant. • PhH-1T provided efficient chemical doping and blend in conjugated polymers. • PhH-1T-doped P3HT organic field-effect transistors improved charge mobility. • Importance of backbone within polymeric dopant for doping was demonstrated. The introduction of extrinsic materials into host materials has been extensively considered for resolving the challenge of intrinsically low charge movement within semiconducting polymers. One of the difficult issues is developing a dopant that can provide a sufficient interfacial area between host and dopant as well as maintain an efficient charge transport pathway without significantly altering the morphological and crystalline properties of semiconducting polymers. Herein, we propose the use of conjugated polyelectrolyte (CPE), a new highly mixable and mutual dopant for achieving enhanced charge mobility in host conjugated polymers. We found that CPE has more homogeneous dispersion in host polymers than non-conjugated polymeric dopants. This results in enhanced charge mobility in the organic field-effect transistor (OFET) based on a novel p-type semiconducting polymer, poly(3-hexylthiophene) (P3HT) (from 0.076 to 0.135 cm2 V−1 s−1). Atomic force microscopy and grazing incident X-ray diffraction measurements were used to confirm the non-destructive behavior of CPE within P3HT. Therefore, it is believed that CPE is promising for use as a homogeneous chemical dopant for polymer semiconductors. [ABSTRACT FROM AUTHOR]

The quaternized conjugated polymer based on poly[(9,9-bis(3′-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dihexylfluorene)] (PFN) as cathode interlayer material (CIM) in a polymer solar cell was systematically investigated. The interlayer consists of alternating dihexyl fluorene and dimethyl aminopropyl fluorene backbone. The corresponding quaternized conjugated polyelectrolytes, named PFN salt and PFN-OH salt, were synthesized by introducing quaternized agents, such as bromoethane or bromoethanol, as side chains onto the PFN precursor polymer. Different quaternized agents give the different inducing effects of an interfacial dipole. The structure of inverted polymer solar cells (iPSCs) is ZnO/interlayer/PTB7-Th:PC71BM/MoO3/Ag. The enhancement in the efficiency of the iPSCs was accomplished by introducing a PFN, PFN salt, and PFN-OH salt as the CIM. Modification of side-chain functionality with bromoethanol shows better performances than that with bromoethane as an interlayer. [ABSTRACT FROM AUTHOR]

Conjugated polyelectrolyte/MWCNT/poly(pyrrole) (CPE-K/MWCNT/PPY) composites have been prepared by a simple solution mixing technique. Synthesis of PPY/CPE/MWCNT composites was characterized by scanning electron microscopy and thermogravimetric analysis. These nanocomposites of CPE-K/MWCNT/PPY were deposited onto a glassy carbon electrode (GCE) in order to fabricate a reliable Mg2+ cationic sensor. A plot called the calibration curve is produced from the current as a function of concentration of Mg2+ ion. This plot was found to be linear in the range 0.1 nM to 0.01 mM, which is defined as the linear dynamic range. According to the surface area of the GCE (0.0316 cm2) and the slope of the calibration curve, a high sensitivity (19.4968 µA µM–1 cm–2) of the Mg2+ ion sensor was calculated. A significant lower limit of detection (97.71 ± 4.89 pM) was obtained in association with a signal to noise ratio of 3. Sensor parameters such as reproducibility, long-time stability, and short response time were measured and found to be quite satisfactory. This new approach to Mg2+ detection with high sensitivity is suggested for application as a novel multifunctional sensing system. Besides, it was found to be very effective to analyze real environmental samples.

Nickel oxide (NiOx) is desirable hole selective material (HSMs) for perovskite photovoltaics because of the characteristic in stability and low cost. However, they deliver limited open‐circuit voltage (VOC) compared to some organic HSMs. As it is known, the performance of perovskite solar cells is predominantly limited by trap‐assisted non‐radiative recombination at the perovskite/hole‐selective layer interfaces. A typical lithium‐doping strategy leads to the valence‐band maximum shift and the electronic levels of NiOx can be tuned robustly to match perovskite active layer in perovskite solar cells. More critically, carrier dynamics studies demonstrate another critical PN4N interlayer strategy reduced interfacial density of defect sites and trap‐assisted recombination. These merits contribute coordinately to lower energy loss across the perovskite/NiOx interface and facilitate charge transport process through the relevant interface, yielding VOC values increase to 1.14 V and power conversion efficiencies over 20%. [ABSTRACT FROM AUTHOR]

Biological photoresponsive ion transport systems consistently attract researchers' attention owing to their remarkable functions of harvesting energy from nature and participating in visual perception systems. Designing and constructing artificial light-driven ion transport devices to mimic biological counterparts remains a challenge owing to fabrication limitations in nanoconfined spaces. Herein, a typical conjugated polyelectrolyte (PFN-Br) was assembled onto a laminated MoS 2 M using simple solution-processing vacuum filtration, resulting in a heterogeneous three- and two-dimensional nanoporous membrane. The designed band alignment between PFN-Br and MoS 2 enables effective directional ion transport under irradiation in an equilibrium solution, even against a 30-fold concentration gradient. The staggered energy structure of PFN-Br and MoS 2 enhances charge separation and establishes a photogenerated potential as the driving force for ion transport. Additionally, the activation energy barrier for ion transport across the heterogeneous membrane decreased by 60% after light irradiation, considerably improving ion transport flux. The easy fabrication and high performance of the membrane in light-powered ion transport provide promising approaches for designing nanofluidic devices with possible applications in energy conversion, light-enhanced biosensing, and photoresponsive ionic devices.

In the present study, we synthesized a new conjugated polyelectrolyte with the N-(α-isobutyryl)pyridinium bromide as substituents via the spontaneous, catalyst-free polymerization of 2-ethynylpyridine using α-bromoisobutyryl bromide. The polymerization proceeded well to give the resulting poly[2-ethynyl-N-(α-isobutyryl)pyridium bromide] in high yield. The polymer structure was characterized by means of such instrumental methods as IR, NMR, and UV-visible spectroscopies to have the conjugated backbone system with the N-(α-isobutyryl)pyridinium bromides. Absorption spectrum of polymer showed the maximum peaks of 334 and 411 nm. The electrochemical property of polymer was measured and discussed. Based on cyclic voltammetry data, this polymer had the HOMO value of 5.25 eV. [ABSTRACT FROM AUTHOR]

We report a colorimetric sensor based on the supramolecular complex between a conformation‐sensitive cationic polythiophene derivative, poly(3‐(4‐methyl‐3‐thienyloxy)propyltrimethylammonium) (PMTPA) and 2‐naphthalenesulfonate (NS). It could be applied to discern 19 primary amino acids by the wavelength of PMTPA/NS. The sensing performance and mechanism was investigated by spectroscopic studies such as absorption and emission spectra. This approach relies on the disassembly of PMTPA/NS aggregates induced by the amphiphilic isoindole derivatives of amino acids formed in situ. 100% confidence limits for this discrimination could be achieved by using linear discriminant analysis (LDA). [ABSTRACT FROM AUTHOR]

Organic photovoltaic (OPV) cells have experienced significant development in the last decades after the introduction of nonfullerene acceptor molecules with top power conversion efficiencies reported over 19% and considerable versatility, for example, with application in transparent/semitransparent and flexible photovoltaics. Yet, the optimization of the operational stability continues to be a challenge. This study presents a comprehensive investigation of the use of a conjugated polyelectrolyte polymer (CPE-Na) as a hole layer (HTL) to improve the performance and longevity of OPV cells. Two different fabrication approaches were adopted: integrating CPE-Na with PEDOT:PSS to create a composite HTL and using CPE-Na as a stand-alone bilayer deposited beneath PEDOT:PSS on the ITO substrate. These configurations were compared against a reference device employing PEDOT:PSS alone, as the HTL increased efficiency and fill factor. The instruments with CPE-Na also demonstrated increased stability in the dark and under simulated operational conditions. Device-based PEDOT:PSS as an HTL reached T80 after 2500 h while involving CPE-Na in the device kept at T90 in the same period, evidenced by a reduced degradation rate. Furthermore, the impedance spectroscopy and photoinduced transient methods suggest optimized charge transfer and reduced charge carrier recombination. These findings collectively highlight the potential of CPE-Na as a HTL optimizer material for nonfluorine OPV cells.

This study describes the formation, size control, and penetration behavior of polymer nanodots (Pdots) consisting of single or few chain polythiophene-based conjugated polyelectrolytes (CPEs) via nanophase separation between good solvent and poor solvent of CPE. Though the chain singularity may be associated with dilution nanophase separation suggests that molecules of a good solvent create a thermodynamically driven solvation layer surrounding the CPEs and thereby separating the single chains even in their poor solvents. This statement is therefore corroborated with emission intensity/lifetime, particle size, and scattering intensity of polyelectrolyte in good and poor solvents. Regarding the augmented features, Pdots are implemented into cell imaging studies to understand the nuclear penetration and to differentiate the invasive characteristics of breast cancer cells. The python based red, green, blue (RGB) color analysis   depicts that Pdots have more nuclear penetration ability in triple negative breast cancer cells due to the different nuclear morphology in shape and composition and Pdots have penetrated cell membrane as well as extracellular matrix in spheroid models. The current Pdot protocol and its utilization in cancer cell imaging are holding great promise for gene/drug delivery to target cancer cells by explicitly achieving the very first priority of nuclear intake., (© 2024 Wiley‐VCH GmbH.)

In this work, we exploit the versatile function of cationic phosphonium-conjugated polythiophenes to develop multifunctional platforms for imaging and combined therapy (siRNA delivery and photodynamic therapy). The photophysical properties (absorption, emission and light-induced generation of singlet oxygen) of these cationic polythiophenes were found to be sensitive to molecular weight. Upon light irradiation, low molecular weight cationic polythiophenes were able to light-sensitize surrounding oxygen into reactive oxygen species (ROS) while the highest were not due to its aggregation in aqueous media. These polymers are also fluorescent, allowing one to visualize their intracellular location through confocal microscopy. The most promising polymers were then used as vectors for siRNA delivery. Due to their cationic and amphipathic features, these polymers were found to effectively self-assemble with siRNA targeting the luciferase gene and deliver it in MDA-MB-231 cancer cells expressing luciferase, leading to 30–50% of the gene-silencing effect. In parallel, the photodynamic therapy (PDT) activity of these cationic polymers was restored after siRNA delivery, demonstrating their potential for combined PDT and gene therapy.

Perovskite defects are a major hurdle in the efficiency and stability of perovskite solar cells (PSCs). While various defect passivation materials have been explored, most are insulators that hinder charge transport. This study investigates the potential of two different π-conjugated polyelectrolytes (CPEs), MPS2-TEA and PCPDTBT2-TMA, as semiconducting additives in PSCs. The CPEs differ in electrical conductivity, offering a unique approach to bridge defect mitigation and charge carrier transport. Unlike previous uses of CPEs mainly as interlayers or charge transport layers, we explore their direct effect on defect passivation within a perovskite layer. Secondary ion microscopy reveals the even distribution of CPEs within the perovskite layer and their efficient defect passivation potential is studied through various spectroscopic analyses. Comparing MPS2-TEA and PCPDTBT2-TMA, we find MPS2-TEA to be superior in defect passivation. The highly conductive nature of PCPDTBT2-TMA due to self-doping diminishes its defect passivation ability. The negative sulfonate groups in the side chains of PCPDTBT2-TMA stabilize polarons, reducing defect passivation capability. Finally, the PSCs with MPS2-TEA achieve remarkable power conversion efficiencies (PCEs) of 22.7% for 0.135 cm 2 and 20.0% for large-area (1 cm 2 ) cells. Furthermore, the device with MPS2-TEA maintained over 87.3% of initial PCE after 960 h at continuous 1-sun illumination and 89% of PCE after 850 h at 85 °C in a nitrogen glovebox without encapsulation. This highlights CPEs as promising defect passivation additives, unlocking potential for improved efficiency and stability not only in PSCs but also in wider applications.

A fluorescent sensing system based on a conjugated polyelectrolyte was constructed to detect dopamine (DA) in complex samples. The conjugated polymer PFPE-PBA with poly[fluorenyl- alt - p -phenyleneethynylene] (PFPE) as the backbone and carrying four pendant phenylboronic acid (PBA) groups in each repeat unit was synthesized. PFPE-PBA was found to have good solubility in polar solvents. After optimization, glycine-NaOH at pH 10 was selected as the buffer, and the solvent composition of the system was set to methanol/water (9/1 by volume). Titration experiments showed that DA could effectively quench the fluorescence of the polymer solution with a response time within 60 s and a limit of detection of 23 nM. Polyols, cations, and other possible interfering substances do not significantly affect the fluorescence of the polymer, thereby allowing for the highly selective detection of DA. Furthermore, quantitative determination of DA in spiked serum and artificial urine samples was successfully demonstrated, with recoveries ranging from 96.7 to 104%. Preliminary mechanism studies suggest that the pedant PBAs capture DA via reaction with the catechol group, and the fluorescence quenching is most likely due to the photoinduced electron transfer between the aromatic part of DA and the conjugated backbone. This study provides a general strategy for the future design of conjugated polyelectrolyte-based sensing systems.

Abstract A platinum(II)-acetylide-based conjugated polyelectrolyte has been designed and synthesized by using polyfluorenes as an O 2 -insensitive fluorophore and Pt(II) complex as an O 2 -sensitive phosphor, which can generate conjugated polyelectrolyte nanoparticle (CPE-nanoparticle) in the aqueous solution owing to their amphiphilic structures. The CPE-nanoparticle displays good sensitivity to O 2 concentration and can detect oxygen levels reversibly. The intracellular ratiometric O 2 sensing performance of the CPE-nanoparticle has been demonstrated by the remarkable variation in the I green / I blue ratio values (0.18–0.85) in HeLa cells under different O 2 levels. Furthermore, O 2 level detection was carried out through time-resolved luminescence imaging (TRLI) to demonstrate the accuracy of the probe based on the CPE-nanoparticle. The CPE-nanoparticle shows a high phosphorescence quantum yield (19.98%) and oxygen quenching efficiency (0.975), which are superior to the existing O 2 probe. The CPE-nanoparticle has been successfully applied in photoluminescence lifetime imaging and time-gated luminescence imaging for monitoring intracellular O 2 levels. Graphical abstract We have designed and synthesized a platinum(II)-acetylide-based conjugated polyelectrolyte, which can generate conjugated polyelectrolyte dots (CPE-Pdots) in water owing to their amphiphilic structures. The CPE-Pdots have been successfully applied in photoluminescence lifetime imaging and time-gated luminescence imaging for monitoring intracellular O 2 concentrations. Image 1 Highlights • A platinum(II)-acetylide based conjugated polyelectrolyte nanoparticle (CPE-nanoparticle) have been prepared. • The intracellular ratiometric O 2 sensing performance of the CPE-Pdots has been demonstrated by the remarkable variation in the I green /I blue ratio values in HeLa cells under different O 2 levels. • The CPE-Pdots have been successfully applied in photoluminescence lifetime imaging and time-gated luminescence imaging for monitoring intracellular O 2 levels, which will remarkably improve the accuracy. [ABSTRACT FROM AUTHOR]

ABSTRACT: A new conjugated polyelectrolyte containing tetraphenylethene units in the backbone is synthesized and characterized. This polyelectrolyte is water‐soluble and exhibits aggregation‐induced emission (AIE) behavior. It is biocompatible and can be directly used in conventional and fluorescence lifetime imaging of mouse neuroblastoma neuro‐2A cells, providing useful information of cellular morphology and intracellular aggregation or motion. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 672–680 [ABSTRACT FROM AUTHOR]

The control of the optoelectronic properties of the interlayers of perovskite solar cells (PSCs) is crucial for achieving high photovoltaic performances. Of the solution-processable interlayer candidates, NiO x is considered one of the best inorganic hole-transporting layer (HTL) materials. However, the power conversion efficiencies (PCEs) of NiO x -based PSCs are limited by the unfavorable contact between perovskite layers and NiO x HTLs, the high density of surface trap sites, and the inefficient charge extraction from perovskite photoactive layers to anodes. Here, we introduce a new organic-inorganic double HTL consisting of a Cu:NiO x thin film passivated by a conjugated polyelectrolyte (PhNa-1T) film. This double HTL has a significantly lower pinhole density and forms better contact with perovskite films, which results in enhanced charge extraction. As a result, the PCEs of PSCs fabricated with the double HTL are impressively improved up to 17.0%, which is more than 25% higher than that of the corresponding PSC with a Cu:NiO x HTL. Moreover, PSCs with the double HTLs exhibit similar stabilities under ambient conditions to devices using inorganic Cu:NiO x . Therefore, this organic-inorganic double HTL is a promising interlayer material for high performance PSCs with high air stability. [ABSTRACT FROM AUTHOR]

To achieve highly efficient organic photovoltaic (OPV) devices, the interface between the photoactive layer and the electrode must be modified to afford the appropriate alignment of the energy levels and to ensure efficient charge extraction at the same time as suppressing charge recombination and accumulation. Recently, p -type conjugated polyelectrolytes (CPEs) have emerged as new hole-transporting materials that can be deposited on electrodes through simple solution processes without additional heat treatment. However, the applications of CPEs have been limited so far because the high electron richness of their conjugated backbones result in low work functions, ∼5.0 eV. Here, by inserting a donor−acceptor (D−A) building block into the CPE backbone, we successfully synthesized a new p -type CPE (PhNa-DTBT), which shows a deep work function above 5.3 eV on several electrodes including Au, Ag, and indium tin oxide. More importantly, PhNa-DTBT produces stable polarons on the polymer backbone and thus achieves a high electrical conductivity of 5.7 × 10 −4 S cm −1 . As a result, an OPV incorporating PhNa-DTBT as a hole-transporting layer was found to exhibit a high performance with a power conversion efficiency of 9.29%. Also, the OPV device shows improved stability in air due to the neutral characteristics of the CPE which is favorable for stabilizing neighbored active and electrode layers. [ABSTRACT FROM AUTHOR]

Synthesis of fluorene-based conjugated polyelectrolytes was achieved via Suzuki polycondensation in water and completely open to air. The polyelectrolytes were conveniently purified by dialysis and analysis of the materials showed properties expected for fluorene-based conjugated polyelectrolytes. The materials were then employed in solar cell devices as an interlayer in conjunction with ZnO. The double interlayer led to enhanced power conversion efficiency of 10.75 % and 15.1 % for polymer and perovskite solar cells, respectively. [ABSTRACT FROM AUTHOR]

A novel cationic water-soluble conjugated polyelectrolyte (CPE) of polyfluorene that contains 15% fraction of 2,1,3-benzothiadiazole (BT) units (PFC3NBT) has been obtained. PFC3NBT demonstrates intramolecular energy transfer from the fluorene segments to BT sites when negatively charged species (SDS or DNAs) are added, following by a shift in emission color from blue to green, has been developed. The high density of positive charges and pendent short alkyl chains of N-propyltrimethylammoniums endow PFC3NBT with high solubility and high fluorescence quantum efficiency of 33.6% in water. The fluorescence emission properties were investigated in the presence of adverse buffer solutions, different surfactants and DNA strands. Interesting fluorescence emission quenching at short wavelength and fluorescence resonance energy transfer (FRET) induced light-on at BT sites were observed and discussed in detail. Very different from previous reports, the fluorescence emission spectra transition happens with an enhancement of integrated fluorescent intensity. The analytes induced a light-up sensing system was studied with a PFC3NBT/SDS complex mode and confirmed with DNA/DNA-FAM sensing systems. More exciting preliminary results on label-free sensing of tumor markers were also reported by investigating the unique fluorescence response to 11 kinds of proteins. These results provide a new insight view for designing CPEs with light-up and label-free features for biomolecular sensing. [ABSTRACT FROM AUTHOR]

We report vacuum-free transfer-printing of silver nanowire (AgNW) network film as a top electrode of polymer light-emitting diodes (PLEDs) using conjugated polyelectrolyte (CPE) interfacial layer. AgNW network is delivered from a donor substrate to the desired area of the devices through an elastomeric polydimethylsiloxane (PDMS) mold stamp. The application of CPE layer with an appropriate thickness on the surface of AgNW and light-emitting polymer (LEP) films provides not only good adhesion between the organic and metal layers but also lowering of the work-function of AgNW electrode for better electron injection at LEP/AgNW interface. PLEDs with laminated AgNW top electrode at the optimized condition show the maximum device efficiencies of 3.81 cd A −1 and 2.99 lm W −1 at 4 V, which are comparable to those of PLEDs with Al cathode. [ABSTRACT FROM AUTHOR]

Sulfonated poly(diphenylacetylene) (SPDPA) is used as an anionic conjugated polyelectrolyte to examine stoichiometric electrostatic self-assembly with homologous cationic surfactants (octadecyl) X(methyl) Y ammonium bromides (O XM YABs) having different numbers of long hydrophobic tails. The SPDPA-O XM YAB complexes formed show significantly increased water contact angle and enhanced fluorescence (FL) emissions compared with the pristine SPDPA. The complexes exist in a gum state at room temperature owing to the plasticizer effect of the hydrophobic tails, hence they are very soft and highly stretchable. The hydrophobicity, softness, and FL quantum efficiency of the SPDPA-O XM YAB complexes increase as the number of hydrophobic tails increases. SPDPA adsorbs uniformly onto filter papers to produce fluorescent papers. The SPDPA-adsorbed papers have many unique applications, including FL image writing, fingerprinting, stamping, and inkjet printing using the surfactant solutions as an ink to reveal high-resolution FL images. In particular, multideposit inkjet-printing using SPDPA and O XM YAB solutions as inks produces water-resistant, embedded figures in paper currency. [ABSTRACT FROM AUTHOR]

A new ratiometric nanosensor is developed for selective and ultrasensitive detection of melamine based on conjugated polyelectrolyte (CPE)-stabilized silver nanoparticles (P1-AgNPs) by perfectly combining the advantages of CPE and AgNPs. P1 featuring a π -delocalized backbone bearing pyridinyl groups can act as an excellent dual-emission fluorescent probe as well as a polymer localizer for AgNPs. In the presence of melamine, the fluorescence intensity at 386 nm increases owing to the turn-on of the fluorescence of P1, whereas FL intensity at 488 nm decreases due to the melamine-induced aggregation and subsequent aggregation-enhanced emission quenching of P1-AgNPs, therefore leading to the ratiometric fluorescent sensing of analyte. Moreover, analyte-induced aggregation of P1-AgNPs also allows the ratiometric colorimetric measurement of melamine. Under the optimum conditions, this facile ratiometric nanosensor favors the fluorescent and colorimetric determination of melamine in liquid milk products with the detection limit as low as 0.1 and 0.45 nM, respectively. [ABSTRACT FROM AUTHOR]

Conjugated polyelectrolytes (CPEs) are emerging as promising materials in the sensor field because they enable high-sensitivity detection of various substances in aqueous media. However, most CPE-based sensors have serious problems in real-world application because the sensor system is operated only when the CPE is dissolved in aqueous media. Here, the fabrication and performance of a water-swellable (WS) CPE-based sensor driven in the solid state are demonstrated. The WS CPE films are prepared by immersing a water-soluble CPE film in cationic surfactants of different alkyl chain lengths in a chloroform solution. The prepared film exhibits rapid, limited water swellability despite the absence of chemical crosslinking. The water swellability of the film enables the highly sensitive and selective detection of Cu 2+ in water. The fluorescence quenching constant and the detection limit of the film are 7.24 × 10 6 L mol -1 and 4.38 nM (0.278 ppb), respectively. Moreover, the film is reusable via a facile treatment. Furthermore, various fluorescent patterns introduced by different surfactants are successfully fabricated by a simple stamping method. By integrating the patterns, Cu 2+ detection in a wide concentration range (nM-mM) can be achieved.

A new conjugated polyelectrolyte material, namely, poly [9,9-bis((6′- N , N , N -trimethylamino)hexyl)-fluorene- alt - co -benzoxadiazole dibromide] (PFBD) is reported as electron transport layer (ETL) in polymer solar cells. We observed a light-soaking effect and described how a pre-UV light treatment on PFBD ETL is essential for attaining higher efficiencies (>7%) and negate the light-soaking problem. The pre-UV light treatment on PFBD layer is found to directly influence its molecular structure and result in reduction of the work function and increased electron mobility in PFBD which corroborates well with the observed lower series resistances obtained from dark current analysis and impedance spectra, and therefore enhancement in open-circuit voltage and fill factor. Moreover, after the pre-UV light treatment, the maximal efficiency of the solar cells retains at a nearly similar level for at least 26 days. [ABSTRACT FROM AUTHOR]

We investigate hybrid tandem solar cells that rely on the combination of solution-processed depleted-heterojunction colloidal quantum dot (CQD) and bulk heterojunction polymer:fullerene subcells. The hybrid tandem solar cell is monolithically integrated and electrically connected in series with a suitable p–n recombination layer that includes metal oxides and a conjugated polyelectrolyte. We discuss the monolithic integration of the subcells, taking into account solvent interactions with underlayers and associated constraints on the tandem architecture, and show that an adequate device configuration consists of a low bandgap CQD bottom cell and a high bandgap polymer:fullerene top cell. Once we optimize the recombination layer and individual subcells, the hybrid tandem device reaches a V OC of 1.3 V, approaching the sum of the individual subcell voltages. An impressive fill factor of 70% is achieved, further confirming that the subcells are efficiently connected via an appropriate recombination layer. [ABSTRACT FROM AUTHOR]