Growth Temperature and Electrochemical Performance in Vapor-Deposited Poly(3,4-ethylenedioxythiophene) Thin Films for High-Rate Electrochemical Energy Storage

摘要： Poly(ethylene 3,4-dioxythiophene (PEDOT) ?lms synthesized by oxidative chemical vapor deposition (oCVD) display strong electrochemical activity in the region from 2 to 4.2 V vs Li/Li+. By contrast, the more commonly studied PEDOT:polystyrenesulfonate (PSS) ?lms have negligible electrochemical activity in this region. For the oCVD ?lms, its small dopant anions (Cl?) that can easily enter and exit the polymer structure allow exchange with the Li+ counterion in solution, while for PEDOT:PSS, the poly(styrenesulfonate) dopant is a large macromolecule having substantially lower mobility. Here, we seek to elucidate the relationship between the structural characteristics of oCVD PEDOT thin ?lms and their electrochemical properties, particularly in Li-ion electrolyte systems. Speci?cally, we seek to rationally design the thin-?lm properties of oCVD PEDOT for high-rate performance and cycle life by varying the ?lm growth temperature. We observe that the dominant e?ect of increasing growth temperature is an in situ reorganization to an edge-on ?lm texture. In this case, the π?π stack is perpendicular to the substrate surface. The alternative dominant texture is face-on dominance, where the π?π stack is parallel to the substrate surface. For the ?rst time, we show that edge-on dominant ?lms provide higher speci?c capacities for a given charge/discharge rate. Furthermore, Raman spectroscopy demonstrates that edge-on dominant ?lms are less susceptible to oxidative damage after long-term cycling. This also enables edge-on dominant ?lms to maintain lower charge-transfer resistances compared to identically cycled face-on ?lms. Edge-on oCVD PEDOT is paired with molybdenum disul?de to demonstrate thick, optimized oCVD PEDOT thin ?lms in asymmetric devices for high-rate electrochemical energy storage.

Ligand-Controlled DArP for n-Type and Ambipolar Mesopolymers

One Step Deposition of PEDOT–PSS on ALD Protected Silicon Nanowires: Toward Ultrarobust Aqueous Microsupercapacitors

摘要： Herein, we propose a fast and simple deposition method of a highly robust pseudocapacitive material based on a straightforward drop-cast of a commercial PEDOT:PSS solution onto 3 nm alumina-coated silicon nanowires. The composite material produced (PPSS-A@SiNWs) displays remarkable capacitive behavior with a specific capacitance of 3.4 mF·cm?2 at a current density of 2 A·g?1 in aqueous Na2SO4 electrolyte. Moreover micro-supercapacitor (MSC) devices based on this material exhibits outstanding lifetime capacity retaining 95% of its initial capacitance after more than 500 000 cycles at a current density of 0.5 A·g?1, a specification which exceeds by far most of the stability of conducting polymers previously reported in the literature. In term of pure energy storage performances, the system is able to reach excellent specific energy and power values of 8.2 mJ·cm?2 and of 4.1 mW·cm?2, respectively, at a high current density of 2 A·g?1. Results are systematically compared to both the state-of-the-art silicon based aqueous on-chip supercapacitors and to that of the pristine alumina-coated silicon nanowires (A@SiNWs) to highlight the contribution of the conductive PEDOT:PSS polymer (PPSS in this study). Hence, the aforementioned one-step deposition represents a simple, cheap and scalable method to thoroughly increase the cycling stability of a well-known conductive polymer, PEDOT?PSS, while drastically increasing the electrochemical performances of an existing technology, the Si NW-based MSCs using aqueous electrolytes.

Recent Developments about Conductive Polymer Based Composite Photocatalysts

摘要： Conductive polymers have been widely investigated in various applications. such as polyaniline (PANI), polypyrrole (PPy), poly(3,4-ethylenedioxythiophene) (PEDOT)), and polythiophene (PTh) have been loaded with various semiconductor nanomaterials to prepare the composite photocatalysts. However, a critical review of conductive polymer-based composite photocatalysts has not been available yet. Therefore, in this review, we summarized the applications of conductive polymers in the preparation of composite photocatalysts for photocatalytic degradation of hazardous chemicals, antibacterial, and photocatalytic hydrogen production. Various materials were systematically surveyed to illustrate their preparation methods, morphologies, and photocatalytic performances. The synergic effect between conductive polymers and semiconductor nanomaterials were observed for a lot of composite photocatalysts. The band structures of the composite photocatalysts can be analyzed to explain the mechanism of their enhanced photocatalytic activity. The incorporation of conductive polymers can result in signi?cantly improved visible-light driven photocatalytic activity by enhancing the separation of photoexcited charge carriers, extending the light absorption range, increasing the adsorption of reactants, inhibiting photo-corrosion, and reducing the formation of large aggregates. This review provides a systematic concept about how conductive polymers can improve the performance of composite photocatalysts.

Fabrication of Chromatic Electronic Textiles Synthesized by Conducting Polymer

摘要： Most of the electronic textiles (e-textiles) were fabricated by carbon-based materials such as graphene, carbon nanotube (CNT), and hybrids of graphene and CNTs due to their high electrical conductivity, flexibility, and good stability. However, it is difficult to synthesize a colored e-textiles because the carbon-based e-textiles have only a black color. In this study, we produced the chromatic e-textiles synthesized with different conductive polymer such as polyaniline, polythiophene, and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate). The chromatic e-textiles were simply fabricated by soaking commercial cotton into an aqueous conductive polymer solution. The chromatic e-textiles were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The electrical conductivity of the chromatic e-textiles was the order of 10?3 S/cm, which was maintained even under bending.

Highly conductive PEDOT:PSS electrode obtained via post-treatment with alcoholic solvent for ITO-free organic solar cells

摘要： We demonstrated a simple and effective processing protocol to improve the electrical conductivity of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films via post-treatment with an alcohol-based solvent, 2-chloroethanol (2-CE), and to enhance their performance as a transparent anode in organic photovoltaic cells (OPVs). Owing to its moderate boiling point, in contrast to previously reported chemicals, 2-CE is advantageous both for handling as a liquid-phase chemical and for drying from the films via evaporation. We compared the optical and electrical properties of the 2-CE-treated PEDOT:PSS with those of standard PEDOT:PSS-based electrodes with the addition of 5 vol% dimethyl sulfoxide (DMSO). With a similar thickness and transmittance in the visible region, the 2-CE-treated polymer electrodes outperformed the DMSO-added films with regard to the electrical conductivity (762 S cm-1 vs. 439 S cm-1). The work functions were almost identical: ~5 eV. We fabricated and characterized organic photovoltaic devices using the anodes and polymer:fullerene blends and found that the 2-CE treatment resulted in higher device performance. Additionally, the 2-CE treatment was applicable to OPVs on a flexible plastic substrate, indicating the effectiveness of the proposed protocol.

Bifacial silicon heterojunction solar cells with advanced Ag-free multi-wire metallization attached to ITO layers using new transparent conductive PAEK copolymers

摘要： Previously, we reported the synthesis and application of transparent conductive polymer (TCP) films, poly(arylene ether ketone) copolymers (co-PAEKs), for forming direct contact between wires and transparent conductive oxide (TCO) layers in silicon solar cells. The polymers have the lowest peak strain temperature (Td), which determines the contact formation temperature, of 205 °C. To utilize such TCP films in silicon heterojunction (SHJ) solar cells with amorphous silicon layers, Td should be lowered. To solve the problem in question, a number of co-PAEKs with a decreased reduced viscosity (ηred) due to a decreased molecular weight of the polymer have been synthesized in this study. It has been shown that lowering ηred from 0.56 to 0.4 dl/g markedly improves the main properties of the co-PAEKs. In particular, (i) Td decreased from 205 to 189 °C, (ii) the peel strength, determined by pulling off the wires from the polymer surface, increased from 1.69 ± 0.26 to 3.55 ± 0.84 N/mm, and (iii) the resistivity of the wire/TCP/ITO (In2O3:Sn) contact, ρC, dropped from 1.20 to 0.67 mΩ cm2. At the same time, the optical properties of the copolymers remained unchanged. We have fabricated bifacial rear junction SHJ solar cells based on a ITO/(n)α-Si:H/(i)α-Si:H/(n)Cz-Si/(i)α-Si:H/(p)α-Si:H/ITO structure, with wire contact grids attached to the ITO layers using co-PAEK films. A solar cell produced using the co-PAEK film with the lowest reduced viscosity had an efficiency under front/rear illumination of 19.6%/18.4%. At 1-sun front illumination and 20/50% of 1-sun rear illumination, the equivalent efficiency is equal to 23.3%/28.8%.

Fabrication of Spray-Coated Semitransparent Organic Solar Cells

摘要： We investigated a promising, low-cost method for fabrication of semitransparent organic solar cells by mass production. The active layer of the organic solar cells was added by spray coating with a dual action airbrush. The solution for the active layer was prepared from a rigorously blended poly(3-hexylthiophene-2,5-diyl) (P3HT) and (6,6)-Phenyl-C61 butyric acid methyl ester (PCBM) in 1,2-dichlorobenzene, and the surface morphology of the spray-coated active layer depending on the concentration of the P3HT and PCBM was investigated. The semitransparency achieved, came from the use of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) as the conductive polymer electrode. For comparison, spin-coated solar cells were also fabricated. Power-conversion efficiency and transparency was achieved from the lower cost spray-coating method that was comparable to those by the traditional spin-coating method. The best spray-coated solar cell exhibited power-conversion efficiency of 1.9% (average or 1.7%) while the best spin-coated solar cell was 2.0% (average of 1.6%), when both were measured under the AM1.5G spectrum 100 mW/cm2 light. Transmittance of the spray-coated solar cell was 52.2% while that of the spin-coated solar cell was 51.2%.

Interfacial nanocomposite sensors (sQRS) for the core monitoring of polymer composites’ fatigue and damage analysis

摘要： The quick development of the smart factory and prognostic and health management (PHM), in the fields of aeronautic, automotive and green energies, is evidencing a need for sensors able to monitor the behavior of composite materials all along their life at the closest of the matter. In situ fabricated conductive polymer nanocomposite (CPC) sensors are bringing an interesting solution to this prospect as they can be integrated homogeneously in the core of composites to probe their deformations and damage. In particular fatigue which is one important mode of failure of polymer composites can be monitored from early signs of damage until the final breakage by analyzing the piezo-resistive response of quantum resistive strain sensors (sQRS) made of carbon nanotubes. We have developed all these aspects in the paper taking the example of a classical glass fibers/epoxy composite instrumented in its core with two sQRS to monitor its short and long term fatigue behavior.

Influence of Water Molecules on the Detection of Volatile Organic Compounds (VOC) Cancer Biomarkers by Nanocomposite Quantum Resistive Vapor Sensors vQRS

摘要： The anticipated diagnosis of various fatal diseases from the analysis of volatile organic compounds (VOC) biomarkers of the volatolome is the object of very dynamic research. Nanocomposite-based quantum resistive vapor sensors (vQRS) exhibit strong advantages in the detection of biomarkers, as they can operate at room temperature with low consumption and sub ppm (part per million) sensitivity. However, to meet this application they need to detect some ppm or less amounts of biomarkers in patients' breath, skin, or urine in complex blends of numerous VOC, most of the time hindered by a huge amount of water molecules. Therefore, it is crucial to analyze the effects of moisture on the chemo-resistive sensing behavior of carbon nanotubes based vQRS. We show that in the presence of water molecules, the sensors cannot detect the right amount of VOC molecules present in their environment. These perturbations of the detection mechanism are found to depend on the chemical interactions between water and other VOC molecules, but also on their competitive absorption on sensors receptive sites, located at the nanojunctions of the conductive architecture. This complex phenomenon studied with down to 12.5 ppm of acetone, ethanol, butanone, toluene, and cyclohexane mixed with 100 ppm of water was worth to investigate in the prospect of future developments of devices analysing real breath samples in which water can reach a concentration of 6%.