Metal Free Conducting PEDOS, PEDOT, and Their Analogues via an Unusual Bromine-Catalyzed Polymerization

Origin of Optoelectronic Contradictions in 3,4-Cycloalkyl[c]-chalcogenophenes: A Computational Study

The planar morphology of the backbone significantly contributes to the subtle optoelectronic features of π-conjugated polymers. On the other hand, the atomistic tuning of an otherwise identical π-backbone could also impact optoelectronic properties systematically. In this manuscript, we compare a series of 3,4-cycloalkylchalcogenophenes by tuning them atomistically using group-16 elements. Additionally, the effect of systematically extending these building blocks in the form of oligomers and polymers is studied. The size of the 3,4-substitution affected the morphology of the oligomers. In addition, the heteroatoms contributed to a further alteration in their geometry and resultant optoelectronic properties. The chalcogenophenes, containing smaller 3,4-cycloalkanes, resulted in lower bandgap oligomers or polymers compared to those with larger 3,4-cycloalkanes. Natural bonding orbital (NBO) calculations were performed to understand the disparity alongside the contour maps of frontier molecular orbitals (FMO).

Ultraviolet Photodetector Based on Poly(3,4-Ethylenedioxyselenophene)/ZnO Core-Shell Nanorods p-n Heterojunction

In this work, we successfully assembled an organic-inorganic core-shell hybrid p-n heterojunction ultraviolet photodetector by the electropolymerization deposition of poly(3,4-ethylenedioxyselenophene) (PEDOS) on the surface of zinc oxide nanoarrays (ZnO NRs). The structures of composite were confirmed by FTIR, UV-Vis, XRD and XPS. Mott-Schottky analysis was used to study the p-n heterojunction structure. The photodetection properties of ZnO NRs/PEDOS heterojunction ultraviolet photodetector were systematically investigated current-voltage (I-V) and current-time (I-t) analysis under different bias voltages. The results showed that PEDOS films uniformly grew on ZnO NRs surface and core-shell structure was formed. The p-n heterojunction structure was formed with strong built-in electric field between ZnO NRs and PEDOS. Under the irradiation of UV light, the device showed a good rectification behavior. The responsivity, detection rate and the external quantum efficiency of the ultraviolet photodetector reached to 247.7 A/W, 3.41 × 10¹² Jones and 84,000% at 2 V bias, respectively. The rise time (τ_r) and fall time (τ_f) of ZnO NRs/PEDOS UV photodetector were obviously shortened compared to ZnO UV photodetector. The results show that the introduction of PEDOS effectively improves the performance of the UV photodetector.

Tunable Protein/Cell Binding and Interaction with Neurite Outgrowth of Low-Impedance Zwitterionic PEDOTs

Zwitterionic poly(3,4-ethylenedioxythiophene) (PEDOT) is an effective electronic material for bioelectronics because it exhibits efficient electrical trade-off and diminishes immune response. To promote the use of zwitterionic PEDOTs in bioelectronic devices, especially for cell alignment control and close electrocoupling, features such as tunable interaction of PEDOTs with proteins/cells and spatially modulating cell behavior are required. However, there is a lack of reliable methods to assemble zwitterionic EDOTs with other functionalized EDOT materials, having different polarities and oxidation potentials, to prepare PEDOTs with the aforementioned surface properties. In this study, we have developed a surfactant-assisted electropolymerization to assemble phosphorylcholine (PC)-functionalized EDOT with other functionalized EDOTs. By adjusting compositions, the interaction of PEDOT copolymers with proteins/cells can be finely tuned; the composition adjustment has an ignorable influence on the impedance of the copolymers. We also demonstrate that the cell-repulsive force generated from PC can spatially guide the neurite outgrowth to form a neuron network at single-cell resolution and greatly enhance the neurite outgrowth by 179%, which is significantly more distinctive than the reported topography effect. We expect that the derived tunable protein/cell interaction and the PC-induced repulsive guidance for the neurite outgrowth can make low-impedance zwitterionic PEDOTs more useful in bioelectronics.

Facile polymerization method for poly(3,4-ethylenedioxythiophene) and related polymers using iodine vapour

A simple polymerization at room temperature using iodine vapour for preparation of PEDOT and PProDOT and their soluble derivatives in neat form.

Recent advances in poly(3,4-ethylenedioxyselenophene) and related polymers

This review highlights the recent progress in synthesis, properties, applications and future outlook of PEDOS based conjugated polymers.

Poly(3,4-ethylenedioxyselenophene): effect of solvent and electrolyte on electrodeposition, optoelectronic and electrochromic properties

In this article, we report the effect of electropolymerization conditions such as solvent and supporting electrolyte on the redox, optoelectronic and electrochromic properties of PEDOS. Monomer EDOS was synthesized by new and simple route and its electropolymerization was investigated by employing six different combinations of solvent–electrolyte namely TBAClO₄/MeCN, TBAPF₆/MeCN, TBABF₄/MeCN, TBAClO₄/PC, TBAPF₆/PC and TBABF₄/PC. Further, the electrochemical, spectroelectrochemistry, morphology and electrochromic properties of resultant PEDOS films were systematically studied. A pronounced effect of both solvent and supporting electrolyte on the electropolymerization, redox, optoelectronic and electrochromic properties on PEDOS film is noted. Among all solvent–electrolyte systems, MeCN and TBAClO₄ were found to be the most suitable medium for electropolymerization of EDOS. Further, PEDOS films prepared in PC showed red shifted absorption maxima, narrow absorption peaks in UV-vis-NIR spectra, slightly more smooth morphologies, and high optical contrasts ratio and coloration efficiency in comparison to MeCN. PEDOS films prepared in TBABF₄/PC exhibited longer λ_max (670 nm), smooth morphology, and the highest optical contrasts ratio (44.6%) and coloration efficiency (141.8 cm² C⁻¹) compared to the other solvent–electrolyte medium.

In this article, we report the effect of electropolymerization conditions such as solvent and supporting electrolyte on the redox, optoelectronic and electrochromic properties of PEDOS.

A bromine-catalysis-synthesized poly(3,4-ethylenedioxythiophene)/graphitic carbon nitride electrochemical sensor for heavy metal ion determination

In this paper, poly(3,4-ethylenedioxythiophene)/graphitic carbon nitride (PEDOT/g-C3N4) composites were prepared by the bromine catalysed polymerization (BCP) method with varying weight ratios of monomer to g-C3N4. For comparison, solid-state polymerization (SSP) and metal oxidative polymerization (MOP) methods were also used for the synthesis of PEDOT/g-C3N4 composites. Electrochemical determination of heavy metal ions (Cd2+ and Pb2+) was carried out by differential pulse voltammetry (DPV) on composite-modified glass carbon electrodes (GCEs), which were prepared by different methods. The obtained composites were analysed by Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible absorption spectroscopy (UV-vis), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results showed that the bromine catalysed polymerization (BCP) method is an effective way to prepare the PEDOT/g-C3N4 composite, and the combination of PEDOT with g-C3N4 can improve the electrochemical activity of electrode materials. And, the composite from the BCP method modified electrode (PEDOT/10 wt% g-C3N4/GCE) exhibited the widest linear responses for Cd2+ and Pb2+, ranging from 0.06-12 μM and 0.04-11.6 μM with detection limits (S/N = 3) of 0.0014 μM and 0.00421 μM, respectively.

Donor-Acceptor-Donor Copolymers with 3,4-Ethylenedioxythiophene Moiety: Electropolymerization and Effect on Optoelectronic and Electrochromic Properties

Three random copolymers PE- co -M1, PE- co -M2, and PE- co -M3 were obtained by electrochemical polymerization of donor-acceptor-donor monomers M1, M2, and M3 with 3,4-ethylenedioxythiophene moiety, respectively, using a 1:1 molar ratio of the corresponding monomers, to find new properties and a more effective way to control the optoelectronic properties in conjugated system. For comparison purpose, polymers P1, P2, and P3 were prepared from the corresponding monomer units M1-M3, respectively, by electrochemical polymerization. We also present efficient synthesis, characterization, and comparative density functional theory (DFT) calculations of the monomers M1-M3 and polymers P1-P3. Cyclic voltammetry, spectroelectrochemistry, and electrochromic properties of all of the polymers P1-P3 and copolymers PE- co -M1, PE- co -M2, and PE- co -M3 were carried out and a throughout comparison was made. We have shown that electrochemical copolymerization is a powerful strategy to tune the highest occupied molecular orbital energy level, band gap, and color of the copolymer. Thus, this finding clearly indicates that the copolymers show significantly different optoelectronic properties compared to their constituent polymers.

Marriage of heavy main group elements with π-conjugated materials for optoelectronic applications

This review article summarizes recent progress in the synthesis and optoelectronic properties of conjugated materials containing heavy main group elements from Group 13-16 as integral components. As will be discussed, the introduction of these elements can promote novel phosphorescent behavior and support desirable molecular and polymeric properties such as low optical band gaps and high charge mobilities for photovoltaic and thin film transistor applications.

Heteroatom Role in Polymeric Dioxyselenophene/Dioxythiophene Systems for Color and Redox Control

The first example of a solution processable dioxythiophene-alt-dioxyselenophene polymer, ProDOT-EDOS, prepared via direct (hetero)arylation polymerization is reported and its optical and electrochemical properties are compared to the all thiophene analog, ProDOT-EDOT, and other relevant dioxythiophene polymers. By substituting the sulfur atom for a selenium atom on one of the monomers in the repeat unit a significant red-shift of both the neutral (41 nm, 132 meV) and polaronic (106 nm, 126 meV) absorbances results, as well as a 160 mV reduction in the onset of oxidation compared to ProDOT-EDOT. Spray-cast films of the polymer electrochemically switch from a vibrant blue charge neutral state to a color neutral and highly transmissive oxidized state.