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This study focused on preparation of stable polymer films of NiII‐ and CoII‐tetraaminophthalocyanines, p‐NiTAPc and p‐CoTAPc, respectively, for highly efficient heterogeneous electrochemical carbon dioxide (CO2) reduction in a flow electrolysis cell. Major development represented in this work was fabrication of p‐NiTAPc and p‐CoTAPc films via electropolymerization of their corresponding monomers on carbon‐based substrates without using binder or conducting additive materials to obtain efficient gas diffusion electrodes (GDEs) for scalable, productive and selective CO2‐to‐CO conversion. The target polymers were characterized by UV‐visible spectrophotometry, attenuated total reflection‐Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X‐ray spectroscopy and cyclic voltammetry. According to controlled potential electrolysis and gas chromatography, p‐NiTAPc‐catalyzed CO2 reduction at −0.99 V vs. reversible hydrogen electrode (RHE) gave 953 mL of CO in a period of 16 hours with current density and Faradaic efficiency (FE) of 109±1 mA ⋅ cm−2 and 99±2 %, respectively. A p‐CoTAPc‐modified GDE exhibited superior catalytic performance to the case of p‐NiTAPc in terms of catalyst stability and CO productivity by performing the continuous CO2 reduction at the potential of −1.10 V vs. RHE for up to 41 hours and affording almost 3 times higher amount of CO with the current density of 161±5 mA⋅cm–2 and 95±2 % FE. [ABSTRACT FROM AUTHOR]

The unprecedented increase in power conversion efficiency (PCE) of low‐cost organo‐inorganic halide perovskite solar cells (OIHPSCs) toward its Shockley‐Queisser limit intriguingly has prompted researchers to investigate the disadvantages of these devices. The issue of operational stability is the main hurdle challenging the way forward for commercialization. To address this, various engineering processes like composition, additives, anti‐solvents, bulk and interface passivation, and deposition techniques have been widely applied to manage both extrinsic and intrinsic factors that induce degradation of the OIHPSCs. In this work, we employed interface passivation, which is an efficient approach to reduce nonradiative recombination. An ultrathin layer of electron donor diketopyrrolopyrrole‐oligothiophene copolymer (DPP860) was applied as an interface passivator between the photoactive layer and [6,6]‐phenyl C61 butyric acid methyl ester (PCBM). The role of the interface passivation on optoelectronic properties of the OIHPSCs was assessed using current density versus voltage (J‐V) characteristics, photoluminescence spectroscopy and time‐resolved photoluminescence spectroscopy. The findings show devices treated with DPP860 exhibit enhanced current density (Jsc) and fill factor, attributing for suppressed nonradiative recombination. Moreover, it shows relative improvement in the stability of the device. The results of this finding reveal that using oligothiophene copolymer can enhance the photovoltaic performance and the stability of inverted OIHPSCs in the ambient environment. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) is identified as a promising reagent for fuel cells, reducing the dependency on carbon‐based fuels. In this work, electrochemically synthesized polymers are employed to improve the efficiency of the oxygen (O2) reduction reaction, thus producing H2O2 in an environmentally friendly way. Two aminoanthraquinones, as well as riboflavin (vitamin B2), are successfully immobilized via oxidative electropolymerization onto both glassy carbon and carbon paper. Of the investigated compounds, polyriboflavin shows a high Faradaic efficiency toward O2 reduction, even at a very low potential of only −0.1 V versus SHE. This catalytic effect is present in neutral and alkaline conditions, using both glassy carbon and carbon paper, but highly pronounced in neutral, aqueous solutions. [ABSTRACT FROM AUTHOR]

Surface‐enhanced Raman scattering (SERS) is a sensitive and fast technique for sensing applications such as chemical trace analysis. However, a successful, high‐throughput practical implementation necessitates the availability of simple‐to‐use and economical SERS substrates. In this work, we present a robust, reproducible, flexible and yet cost‐effective SERS substrate suited for the sensitive detection of analytes at near‐infrared (NIR) excitation wavelengths. The fabrication is based on a simple dropcast deposition of silver or gold nanomaterials on an aluminium foil support, making the design suitable for mass production. The fabricated SERS substrates can withstand very high average Raman laser power of up to 400 mW in the NIR wavelength range while maintaining a linear signal response of the analyte. This enables a combined high signal enhancement potential provided by (i) the field enhancement via the localized surface plasmon resonance introduced by the noble metal nanomaterials and (ii) additional enhancement proportional to an increase of the applicable Raman laser power without causing the thermal decomposition of the analyte. The application of the SERS substrates for the trace detection of melamine and rhodamine 6G is demonstrated, which shows limits of detection smaller than 0.1 ppm and analytical enhancement factors on the order of 104 as compared to bare aluminium foil. [ABSTRACT FROM AUTHOR]

Herein, the magnetic field effect on the source–drain current of organic field‐effect transistors with semiconductor layers made of H‐bonded pigments is studied. In all devices, an external magnetic field reduces the source–drain current in the transistor. The magnetic field effect is independent of the direction of the applied magnetic field. The observed increase of the magnetoresistance seems to originate from the used semiconductor or the semiconductor–dielectric interface and is not influenced by the nature of the gate electrodes or the semiconductors' deposition procedure (e.g., grain size, layer thicknesses, etc.). As all prepared devices do have single charge carrier nature, the formation of bipolarons is suggested to be responsible for the observed magnetic field effect. The presented experiments demonstrate that hydrogen‐bonded semiconductors behave no different than their classical van der Waals‐bonded fully conjugated semiconductors' counterparts. [ABSTRACT FROM AUTHOR]

Homogeneous, aqueous solutions of the natural compound riboflavin were investigated for their electrocatalytic oxygen to hydrogen peroxide (H2O2) reduction performance using cyclic voltammetry and electrolysis. In addition to pH dependencies, interestingly the choice of carbon‐based electrode material had a strong impact on the electrocatalytic performance. Therefore, the three electrode materials, glassy carbon, carbon paper (CP), and carbon felt were electrochemically compared and afterwards investigated with scanning electron microscopy. Attributed to the deprotonation of riboflavin, pH = 13 was identified as the best performing condition. Using CP at pH = 13, the addition of riboflavin enhanced the H2O2 production by a factor of 14 up to 355 μmol after 6 h at an average faradaic efficiency of around 80%. [ABSTRACT FROM AUTHOR]

Natural dielectrics are emerging nowadays as a niche selection of materials for applications targeting biocompatibility and biodegradability for electronics and sensors within the overall effort of scientific community to achieve sustainable development and to build environmental consciousness. The two natural resins analyzed in this study, silver fir and Rocky mountain fir demonstrate robust dielectric properties and excellent film forming capabilities, while being trap free dielectrics in high‐performance organic field effect transistors (OFETs) operating at voltages as low as 1 V. Immense research possibilities are demonstrated through the avenue of inorganic nanofillers insertions in the natural resins film, that opens the door for fabrication of very low voltage OFETs with high dielectric constant insulating layers. [ABSTRACT FROM AUTHOR]

This research presents a new series of tetrabenzoporphyrins (TBPs) bearing p‐diphenylaminophenylethynyl and p‐carboxylphenylethynyl groups or two p‐carboxylphenylethynyl groups in a trans‐fashion on a TBP core for photoelectrochemical O2 reduction. Impact of electron‐donating diphenylamino and electron‐withdrawing surface‐anchoring carboxyl groups on photophysical and electrochemical properties of the target TBPs was experimentally and theoretically investigated in comparison with those of their benchmark analog. The results show that while the p‐carboxylphenylethynyl group give an electronic contribution to the molecules by lowering energy gap, the role of the p‐diphenylaminophenylethynyl group is found to be trivial. Preliminary investigation on electrochemical O2 reduction indicates significant catalytic activities of TBP‐modified TiO2/fluorene‐doped tin oxide electrodes at potentials of −0.2 V and −0.3 V vs. normal hydrogen electrode (NHE) in a pH‐neutral and ambient aqueous condition, leading to H2O2 formation. Upon photoirradiation, catalytic performance of such TBP‐based electrodes is further enhanced with the optimum yield obtained when the dicarboxyl derivatives and the potential of −0.3 V vs. NHE are applied. Proposed photoinjection mechanism of the dye/TiO2 simulated by time‐dependent density functional theory calculations supported the experimental results indicating the favorable role of the target TBPs as photoelectrocatalysts in the O2 reduction. [ABSTRACT FROM AUTHOR]

Millimeter‐long organic fiber arrays of intramolecular charge transfer merocyanine HB194 dye were prepared by evaporation‐induced self‐assembled method. X‐ray diffraction spectroscopy indicated individual fibers are millimeter‐sized HB194 single crystals. The elimination of defects and structural disorder enabled photoluminescence microscopy studies that revealed the intramolecular charge transfer (CT), bandgap excitonic state is long‐lived and remains largely localized in the absence of π‐orbital stacking in the crystalline structure. These nanosecond lifetimes explain the observation of a photoconductivity response upon irradiation with a 633 nm laser due to dissociation of the delocalized CT exciton to free carriers. At the same time, the photo response was increased 4.5 times by coating of the HB194 fiber array with polyvinyl alcohol. This increase is attributed to the larger dielectric field around the fibers that further facilitates the band‐gap (CT) exciton dissociation. [ABSTRACT FROM AUTHOR]

The synthesis, experimental and theoretical study of the novel air‐stable four adamantane‐bearing dyes based on the trans‐epindolidione (EPI) and trans‐quinacridone (QA) cores are presented. Compared to the parent EPI and QA, the methyl‐/ethyladamantyl substitution ensures that their structural stability in crystals is preserved due to the self‐organizing properties of adamantyl groups. The investigated materials are solution‐processable in common organic solvents and possess excellent thermal stability. The very good solubility was achieved by a one‐step short and easy synthesis, which resulted in moderate yields of a new family of synthesized dyes. The ethyladamantyl EPI derivative (3) exhibits a unique rise in thermal stability reaching 412 °C. The resulting electrochemical band gap carried out on thin‐film evaporated on ITO‐coated glass electrodes was in the range of 2.4–2.5 eV. The experimental HOMO energies range from −6.2 to −6.0 eV, and LUMO energies lay between −3.7 and −3.5 eV. The prepared compounds are characterized by strong fluorescence in solutions and in powder, suggesting a decrease in the extent of non‐radiative relaxation processes. [ABSTRACT FROM AUTHOR]

The majority of energy storage devices like batteries, fuel cells or electrolyzers require heterogeneous electrodes. Immobilization of redox‐active organic molecules by a polymeric approach seems to be a promising route towards organic electrodes for electrocatalytic energy storage or in batteries. Although numerous reports on synthesis and application of new poly‐anthraquinones exist, a universal guideline or tool for selection of the best polymer, concerning several energy storage applications, is still underdeveloped. Moving into the direction of developing such a tool, we have selected and synthesized three poly(anthraquinones). NMR, FTIR, UV‐Vis, TGA, contact angle measurement and SEM revealed certain structure‐property trends, which can be correlated with the performance in the electrochemical investigation. The insights gained within this work demonstrate correlations between the FTIR frequencies and the electrochemical reduction potential, as well as between the polymer hydrophobicity and the electrochemical performance. [ABSTRACT FROM AUTHOR]

Important parameters of an organic semiconductor material are the electronic band gap (Eg) and the position of highest occupied and lowest unoccupied bands versus vacuum. These bands are called valence and conduction band for inorganic semiconductors. For organic semiconductors the bands defining the band gap are often called highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). One advantage of semiconducting polymers is the ability to tune the band gap and the position of HOMO and LUMO levels by molecular chemical design. The organic photovoltaic solar cells need absorbers with a smaller bandgap to maximize the power conversion efficiency of these devices. There are several chemical strategies to synthesize low band gap polymers for optoelectronic applications. In this manuscript, an updated overview on the current status of these low band gap conjugated polymers will be given. The design principles of low band gap polymers, the properties of the resulting materials, and important applications and devices realized with this material class will be briefly discussed. [ABSTRACT FROM AUTHOR]

X‐ray detectors play a pivotal role in development and advancement of humankind, from far‐reaching impact in medicine to furthering the ability to observe distant objects in outer space. While other electronics show the ability to adapt to flexible and lightweight formats, state‐of‐the‐art X‐ray detectors rely on materials requiring bulky and fragile configurations, severely limiting their applications. Lead halide perovskites is one of the most rapidly advancing novel materials with success in the field of semiconductor devices. Here, an ultraflexible, lightweight, and highly conformable passively operated thin film perovskite X‐ray detector with a sensitivity as high as 9.3 ± 0.5 µC Gy−1 cm−2 at 0 V and a remarkably low limit of detection of 0.58 ± 0.05 μGy s−1 is presented. Various electron and hole transporting layers accessing their individual impact on the detector performance are evaluated. Moreover, it is shown that this ultrathin form‐factor allows for fabrication of devices detecting X‐rays equivalently from front and back side. [ABSTRACT FROM AUTHOR]

The issue of long‐term stability is one of the main obstacles challenging the progress of perovskite solar cells (PSCs). To alleviate this issue, a thorough understanding of the degradation mechanisms of the device is required. Herein, electrochemical impedance measurements in combination with maximum power point (MPP) tracking are applied to characterize PSCs, aiming to gain an understanding of the charge carrier dynamics in the photoactive bulk and at the contact‐absorber‐interfaces under operation. Electrochemical impedance spectroscopy (EIS) results show that the device charge transport resistance and interface capacitance associated with charge accumulation at the interfaces are both increasing upon continuous operation. This suggests ion migration from the photoactive perovskite layer to the charge transport layer interfaces leaving defects in the bulk. This suggests that reduction of the device performance upon continuous operation is mainly related to the changes in the bulk of the photoactive perovskite film and ions migration. [ABSTRACT FROM AUTHOR]

In this work, the preparation of conducting polymer‐based composites using a biological anionic polymer based on salmon deoxyribonucleic acid (DNA) is presented. The most commonly used polymers poly(3,4‐ethylenedioxythiophene) (PEDOT), as well as polypyrrole, are polymerized in the presence of DNA. Since conjugated polymers are in the polycationic state in their electrically conducting form, the role of the counterion is now fulfilled by the low cost biomolecule DNA as an alternative material, which is also a polyanion thanks to its phosphate chain. The resulting synthesized material is a conducting polymer–DNA biocomposite. Such materials are highly attractive for the rising field of bioelectronics and biosensors, especially in organic electrochemical transistors (OECTs) and ion pumps. OECTs made of these conducting polymer biocomposites are fabricated and their electrochemical device operation is compared to the most widely used PEDOT:polystyrenesulfonate. [ABSTRACT FROM AUTHOR]

Abstract: We report on a self‐assembled system comprising a molecular copper‐porphyrin photoelectrocatalyst, 5‐(4‐carboxy‐phenyl)‐10,15,20‐triphenylporphyrinatocopper(II) (CuTPP‐COOH), covalently bound to self‐organized, anodic titania nanotube arrays (TiO2 NTs) for photoelectrochemical reduction of oxygen. Visible light irradiation of the porphyrin‐covered TiO2 NTs under cathodic polarization up to −0.3 V vs. Normal hydrogen electrode (NHE) photocatalytically produces H2O2 in pH neutral electrolyte, at room temperature and without need of sacrificial electron donors. The formation of H2O2 upon irradiation is proven and quantified by direct colorimetric detection using 4‐nitrophenyl boronic acid (p‐NPBA) as a reactant. This simple approach for the attachment of a small molecular catalyst to TiO2 NTs may ultimately allow for the preparation of a low‐cost H2O2 evolving cathode for efficient photoelectrochemical energy storage under ambient conditions. [ABSTRACT FROM AUTHOR]

Conductive polymers represent a rare case in which free-carrier absorption is shifted to the far-infrared-an attractive advantage in light of the requirement of highly transparent conductors across the visible and near-infrared. Unfortunately, prior approaches to doping these polymers-imperative for high conductance-have consistently led to strong localization arising from fluctuating band alignment among polymer chains. Here, this study overcomes this problem of doping-induced Anderson localization for the first time in polymers by developing a new conductive polymer synthesis strategy. This study achieves polymerization and doping simultaneously, thereby using an alternative nonmetal oxidant and thereby avoiding the introduction of excess energy that normally arises from exergonic polymerization. The resulting conductive polymer is the first to provide electron coherence in a metallic polymer thin film. The conductivity reaches a remarkable 3300 S cm−1 at 1.8 K and the mean electron scattering length a record 330 Å. This enhancement drives the glassy metal transition in the vicinity of the Mott-Ioffe-Regel (MIR) limit. The new metallic polymer achieves 10−2 Ω−1 figure of merit, making it a contender for transparent conductive contacts previously only accessible using inorganics. The new material offers a uniquely broad transparency window spanning the UV to the mid-infrared. [ABSTRACT FROM AUTHOR]

We present a study on a microbial electrolysis cell with methanogenic microorganisms adapted to reduce CO2 to CH4 with the direct injection of electrons and without the artificial addition of H2 or an additional carbon source except gaseous CO2. This is a new approach in comparison to previous work in which both bicarbonate and gaseous CO2 served as the carbon source. The methanogens used are known to perform well in anaerobic reactors and metabolize H2 and CO2 to CH4 and water. This study shows the biofilm formation of those microorganisms on a carbon felt electrode and the long-term performance for CO2 reduction to CH4 using direct electrochemical reduction. CO2 reduction is performed simply by electron uptake with gaseous CO2 as the sole carbon source in a defined medium. This 'electrometabolism' in such microbial electrolysis cells depends strongly on the potential applied as well as on the environmental conditions. We investigated the performance using different adaption mechanisms and a constant potential of −700 mV vs. Ag/AgCl for CH4 generation at 30-35 °C. The experiments were performed by using two-compartment electrochemical cells. Production rates with Faradaic efficiencies of around 22 % were observed. [ABSTRACT FROM AUTHOR]

A family of porphyrins and benzoporphyrins bearing phenyl, thiophenyl, or bithiophenyl groups at their meso-positions are synthesized and systematically investigated for their potential use in bulk heterojunction solar cells (BHJ-SCs). Comparative studies of these compounds show that the introduction of the thiophenyl and bithiophenyl groups, and the extension of the porphyrin π-conjugated system significantly affect both photophysical and electrochemical properties. Binary conventional and ternary converted BHJ-SCs based on these compounds are fabricated and studied. Results show that remarkable enhancement of the device efficiency is achieved by using the thiophene-containing benzoporphyrin derivatives as additives for a poly(3-hexylthiophene) (P3HT):phenyl-C61-butyric acid methyl ester blend in the inverted BHJ-SCs. The optimum BHJ-SC exhibits a maximum energy conversion efficiency of 4.3%, corresponding to 19% enhancement of the conversion efficiency as compared with the benchmark BHJ-SCs. [ABSTRACT FROM AUTHOR]

Research on semiconductor photocatalysts for the conversion of solar energy into chemical fuels has been at the forefront of renewable energy technologies. Water splitting to produce H2 and CO2 reduction to hydrocarbons are the two prominent approaches. A lesser-known process, the conversion of solar energy into the versatile high-energy product H2O2 via reduction of O2 has been proposed as an alternative concept. Semiconductor photoelectrodes for the direct photosynthesis of H2O2 from O2 have not been applied up to now. Photoelectrocatalytic oxygen reduction to peroxides in aqueous electrolytes by hydrogen-bonded organic semiconductor is observed photoelectrodes. These materials have been found to be remarkably stable operating in a photoelectrochemical cell converting light into H2O2 under constant illumination for at least several days, functioning in a pH range from 1 to 12. This is the first report of a semiconductor photoelectrode for H2O2 production, with catalytic performance exceeding prior reports on photocatalysts by one to two orders of magnitude in terms of peroxide yield/catalyst amount/time. The combination of a strongly reducing conduction band energy level with stability in aqueous electrolytes opens new avenues for this widely available materials class in the field of photo(electro) catalysis. [ABSTRACT FROM AUTHOR]

We present results for direct bio-electrocatalytic reduction of CO2 to C1 products using electrodes with immobilized enzymes. Enzymatic reduction reactions are well known from biological systems where CO2 is selectively reduced to formate, formaldehyde, or methanol at room temperature and ambient pressure. In the past, the use of such enzymatic reductions for CO2 was limited due to the necessity of a sacrificial co-enzyme, such as nicotinamide adenine dinucleotide (NADH), to supply electrons and the hydrogen equivalent. The method reported here in this paper operates without the co-enzyme NADH by directly injecting electrons from electrodes into immobilized enzymes. We demonstrate the immobilization of formate, formaldehyde, and alcohol dehydrogenases on one-and-the-same electrode for direct CO2 reduction. Carbon felt is used as working electrode material. An alginate-silicate hybrid gel matrix is used for the immobilization of the enzymes on the electrode. Generation of methanol is observed for the six-electron reduction with Faradaic efficiencies of around 10 %. This method of immobilization of enzymes on electrodes offers the opportunity for electrochemical application of enzymatic electrodes to many reactions in which a substitution of the expensive sacrificial co-enzyme NADH is desired. [ABSTRACT FROM AUTHOR]

The major challenge in organic electronics concerns the stability of organic semiconductor materials which affects the operational lifetime of devices. Recent reports have shown that hydrogen-bonded pigments of the indigoid family are air- and moisture resistant. The magenta pigment quinacridone, a hydrogen-bonded molecule in the solid state with a pentacene like frame, is a perfect example for extraordinary chemical stability. Here, studies using in situ spectroscopic methods comparing quinacridone and pentacene are presented. A different spectral response of their radical cations is observed upon chemical doping. While in pentacene the barrier between doping and irreversible overoxidation is small, this stability toward overoxidation is increased by the heteroatomic structure, leading to hydrogen-bonded quinacridone. This work provides insight into molecular design principles that may lead to next-generation organic semiconductors with enhanced stability and performance. [ABSTRACT FROM AUTHOR]

Thin film electronics fabricated with non-toxic and abundant materials are enabling for emerging bioelectronic technologies. Herein complementary-like inverters comprising transistors using 6,6′-dichloroindigo as the semiconductor and trimethylsilyl-cellulose (TMSC) films on anodized aluminum as bilayer dielectric layer are demonstrated. The inverters operate both in the first and third quadrant, exhibiting a maximum static gain of 22 and a noise margin of 58% at a supply voltage of 14 V. (© 2015 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Poly(phenylene ethynylene)- alt-poly(phenylene vinylene)s (PPE-PPVs) with various thiophene units (thiophene, bithiophene, and 3,4-ethylenedioxythiophene) at the X position, with the general backbone design (PhCC XCCPhCHCHPhCHCH), bearing identical solubilizing side chains at the phenylene rings of the polymers, are synthesized to study the effect of this structural alteration on the properties such as the photophysics, the electrochemical properties, the charge-carrier mobility, and the morphology of the materials and its impact on their photovoltaic performance. The polymers are obtained in good yields with reasonable molecular weights and show solubility in ordinary organic solvents required for solution-processing applications. The polymer with a basic thiophene ring at the X positions shows the highest open-circuit voltage ( VOC of 930 mV) and the polymer with a bithiophene unit at the X position shows the highest short-circuit current density and charge-carrier mobility, whereas the polymer with 3,4-ethylenedioxythiophene shows the lowest photovoltaic performance. [ABSTRACT FROM AUTHOR]

Limiting anthropogenic carbon dioxide emissions constitutes a major issue faced by scientists today. Herein we report an efficient way of controlled capture and release of carbon dioxide using nature inspired, cheap, abundant and non-toxic, industrial pigment namely, quinacridone. An electrochemically reduced electrode consisting of a quinacridone thin film (ca. 100 nm thick)on an ITO support forms a quinacridone carbonate salt. The captured CO² can be released by electrochemical oxidation. The amount of captured CO² was quantified by FT-IR. The uptake value for electrochemical release process was 4.61 mmolg-1. This value is among the highest reported uptake efficiencies for electrochemical CO² capture. For comparison, the state-of-the-art aqueous amine industrial capture process has an uptake efficiency of ca. 8 mmolg-1. [ABSTRACT FROM AUTHOR]

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Rhenium(I) carbonyl complexes carrying substituted bis(arylimino)acenaphthene ligands (BIAN-R) have been tested as potential catalysts for the two-electron reduction of carbon dioxide. Cyclic voltammetric studies as well as controlled potential electrolysis experiments were performed using CO2-saturated solutions of the complexes in acetonitrile and acetonitrile-water mixtures. Faradaic efficiencies of more than 30 % have been determined for the electrocatalytic production of CO. The effects of ligand substitution patterns and water content of the reaction medium on the catalytic performance of the new catalysts are discussed. [ABSTRACT FROM AUTHOR]

ABSTRACT An anthracene-containing poly(arylene-ethynylene)- alt-poly(arylene-vinylene) (PAE-PAV) of general constitutional unit (PhCCAnthrCCPhCHCHAnthrCHCH) n bearing two 2-ethylhexyloxy solubilizing side chains on each phenylene (Ph) unit has been synthesized and characterized. The basic electrochemical characterization was done, showing the existence of two non-reversible oxidation and one reversible reduction peaks. The optical properties, the real and imaginary part of the dielectric function, were probed using spectroscopic ellipsometry (SE). The vibrational structure of the undoped/doped polymer was investigated using Fourier transformed infrared spectroscopy. A strong change in the polaronic absorption was observed during the doping, which after modeling revealed the existence of two separated transitions. The optical changes upon doping were additionally recorded using the SE technique. Similar to the results from FT-IR spectroscopy, two new in-the-gap absorptions were found. Moreover, the electrical conductivity as well as the mobility of positive carriers were measured. In the undoped state, the conductivity of the polymer was found to be below the detection limit (<μS cm−1), after doping the conductivity increased to 0.69 S cm−1. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 338-346 [ABSTRACT FROM AUTHOR]

The alkynyl-substituted ReI complex [Re(5,5′-bisphenylethynyl-2,2′-bipyridyl)(CO)3Cl] was immobilized by electropolymerization onto a Pt-plate electrode. The polymerized film exhibited electrocatalytic activity for the reduction of CO2 to CO. Cyclic voltammetry studies and bulk controlled-potential electrolysis experiments were performed by using a CO2-saturated acetonitrile solution. The CO2 reduction, determined by cyclic voltammetry, occurs at approximately −1150 mV versus the normal hydrogen electrode (NHE). Quantitative analysis by GC and IR spectroscopy was used to determine a Faradaic efficiency of approximately 33 % for the formation of CO. Both values of the modified electrode were compared to the performance of the homogenous monomer [Re(5,5′-bisphenylethynyl-2,2′-bipyridyl)(CO)3Cl] in acetonitrile. The polymer formation and its properties were studied by using SEM, AFM, and attenuated total reflectance (ATR) FTIR and UV/Vis spectroscopy. [ABSTRACT FROM AUTHOR]

The conjugated polymer AnE‐PVstat demonstrates competitive photovoltaic characteristics compared with modern “push‐pull” polymer systems. AnE‐PVstat is distinguished by its PPV‐type molecular structure, the absence of heterocyclic units, particularly thiophene rings, and the presence of an anthracene unit bearing two adjacent triple bonds. AnE‐PVstat in combination with specially designed [60]fullerene derivatives F3 and F11 shows power conversion efficiencies of >4% in solar cells. [ABSTRACT FROM AUTHOR]

We describe the history of indigo dye and its derivative Tyrian purple, from their roles in the ancient world to recent research showing the semiconducting properties of indigoids. Indigoids are natural dyes that have been produced for centuries, and indigo is currently the most produced dye worldwide. Herein we review the history of these materials, their chemistry and physical properties, and their semiconducting characteristics in the solid state. Due to hydrogen bonding and π-stacking, indigo and Tyrian purple form highly-ordered crystalline thin films. Such films have been used to fabricate high-performance organic field-effect transistors with ambipolar charge transport, as well as complementary-like circuits. Mobility values were found to be in the range of 10−2-0.4 cm2/Vs. With performance on par with the best available organic semiconductors, indigoids demonstrate the potential of sustainable electronics based on biodegradable and biocompatible materials. [ABSTRACT FROM AUTHOR]