A Free‐standing electrochromic material of poly(5,7‐bis(2‐(3,4‐ethylenedioxy)thienyl)‐indole) and its application in electrochromic device

Free‐standing poly(5,7‐bis(2‐(3,4‐ethylenedioxy)thienyl)‐indole) (PETI) was electrochemically obtained from 5,7‐bis(2‐(3,4‐ethylenedioxy)thienyl)‐indole (ETI) prepared by Stille coupling reaction of 5,7‐dibromoindole and 3,4‐ethylenedioxythiophene. For comparison, poly(5,7‐bis(2‐thiophene)‐indole) was also electrosynthesized from 5,7‐bis(2‐thiophene)‐indole (BTI) which was prepared from the 5,7‐dibromoindole and thiophene. Characterizations of ETI and BTI were performed by cyclic voltammetry, scanning electron microscopy, ¹H NMR, and ¹³C NMR spectroscopy. Spectroelectrochemical studies showed PETI had better electrochromic properties and showed two different colors (brown and blue‐violet) under various potentials with better maximum contrast (ΔT%) and coloration efficiency (CE). An electrochromic device (ECD) based on PETI and poly(3,4‐ethylenedioxythiophene) (PEDOT) was also constructed and characterized. This ECD had fast response time, high CE, better optical memory, and long‐term stability. These results indicated that PETI had potential applications for ECD. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 2356–2364     

Synthesis and electropolymerization of 5,12-dihydrothieno[3′,4′:2,3][1,4]dioxocino[6,7-b]quinoxaline and its electrochromic properties

Synthesis of a new thiophene-based monomer; 5,12-dihydrothieno[3′,4′:2,3][1,4]dioxocino[6,7-b]quinoxaline (DDQ), was realized. The chemical structure of the monomer was characterized by ¹H NMR, FTIR and mass spectroscopy techniques. Electrochemical polymerization of DDQ and characterization of the resulting polymer [P(DDQ)] was performed. Moreover, the spectroelectrochemical and electrochromic properties of the polymer film were investigated. P(DDQ) has a low oxidation potential (0.9 V) and low band gap (1.73 eV) compared to polythiophene. In addition, dual-type polymer electrochromic device (ECD) based on P(DDQ) with poly(3,4-ethylenedioxythiophene) (PEDOT) was constructed. Spectroelectrochemistry, electrochromic switching, stability and open-circuit stability of the device were studied. It was observed that polymer have good switching time, reasonable contrast and optical memory.     

Maximum contrast from an electrochromic material

A general procedure to calculate the maximum contrast from an electrochromic material is presented. The obtained results were tested by spectroelectrochemical studies of two different conducting polymer films: poly-3, 4-ethylenedioxy-thiophene (PEDOT) and poly-3,6-bis(2-(3,4-ethylenedioxy)thienyl)-N-methylcarbazole (PBEDOT-NMCz). The presented methodology constitutes a useful tool for the optimization of electrochromic devices.     

A new electrochromic material from an indole derivative and its application in high-quality electrochromic devices

A novel electrochromic material, poly(indole-6-carboxylic acid) (PIn), and its application in electrochromic devices (ECDs) are discussed. PIn was switched between yellow in the reduced state and green in the oxidized state. Electrochromic switching of PIn film shows that it has fast switching time and high optical contrast. ECD based on PIn and poly(3,4-ethylenedioxythiophene) (PEDOT) was also fabricated and characterized. The response time of this device was found to be 1.0 s and the optical contrast was 45%. The coloration efficiency (CE) was calculated to be 510 cm² C^?1. Clear change from green (neutral) to blue-violet color (oxidized) of ECD is demonstrated with robust cycle life. These results provide an avenue for applications of polyindole family in electrochromic devices.     

Electrochemical Synthesis and Optical Properties of a Chiral Poly[1,4‐bis(3′,4′‐ethylenedioxythienyl)‐phenylene] Derivative

Summary: Optically active poly[(R)‐ or (S)‐1,4‐bis(2‐(3′,4′‐ethylenedioxy)thienyl)‐2‐benzoic acid 1‐methylheptyl ester] was prepared by an electrochemical technique and characterized by circular dichroism measurements. It was found that the optical activity and optical rotation of the film could be controlled by adjusting the electronic state of the electrochemical process. Polymer films prepared in the oxidized state exhibit a weak Cotton effect, while the reduced polymer film exhibits the expected mirror‐image bisignate Cotton effect in the region of the π–π* transition of the polymer main chain. These results indicate that the main chain itself is chiral in the film state. This procedure has great potential for the preparation of functional electrochromic devices and the improved preparation of durable electrochromic devices based on the good film‐forming properties of the chiral polymer.

Cyclic voltammogram and CD spectra of the chiral polymer thin film produced here.     

Tuning the band gap of easily oxidized bis(2-thienyl)– and bis(2-(3,4-ethylenedioxythiophene))–phenylene polymers

The synthesis, characterization and electrochemical polymerization, along with redox switching behavior of the resultant polymers, of 1,4-bis(2-(3,4-ethylenedioxy)thienyl)–2,5-difluorobenzene ( 1 ) and 1,4-bis(2-thienyl)–2,5-difluorobenzene ( 2 ) is presented. Compounds 1 and 2 were synthesized by a Pd°-catalyzed cross-coupling and in good yields (85% and 84%, respectively). Both monomers electropolymerize to form electroactive redox switchable films, with the more electron-rich 3,4-ethylenedioxythiophene derivative polymerizing and switching at lower potentials. The electronic band gaps were determined to be 1.9 eV for P1 and 2.3 eV for P2. Thin films of P1 and P2 were found to be electrochromic and exhibit color changes of red-to-blue/black for P1 and yellow-to-black for P2. These results are compared with various substituted bis(heterocycle)benzene derivatives in order to present a series of structure to property relationships. © 1998 John Wiley & Sons, Ltd.     

Electrochromic films of a methylcarbazole derivative: optimization of polymerization and optical contrast

The effect of the polymerization potential and time on the electrochemical and optical responses of electrogenerated films of poly-[3,6-bis(2-(3,4-ethylenedioxy)thienyl)-N-methylcarbazole] (PBEDOT-NMCz) was studied. Every electrogenerated film was characterized according to the charge consumed during polymerization, its redox charge density (calculated by integration of a control voltammogram), the efficiency of the polymerization process (defined as the charge consumed during electropolymerization to create one redox site), and its optical contrast. Within the studied polymerization potential range, 0.75 to 2 V, the charge consumed during polymerization increased with the potential, while the efficiency of the polymerization process decreased. The redox site production rate reached a maximum at 1.25 V. The optical contrast of the obtained films remained the same when polymerizing in the range between 0.75 and 1.25 V. Polymerization at more anodic potentials resulted in films of lower electrochromic quality (defined as the maximum contrast achievable). The optimal conditions for electropolymerization in terms of optimum energy consumption and the best electrochromic quality of the films were established.     

High‐performance Flexible Complementary Electrochromic Device Based on Plasma Modified WO3 Nano Hybrids and V2O5 Nanofilm with Low Operation Voltages

Tungsten trioxide‐poly(3,4‐ethylenedioxythiophene) (WO₃‐PEDOT) and tungsten trioxide‐polyfuran (WO₃‐PFu) were prepared by rf rotating plasma polymerization. Electrochromic hybrid thin films were fabricated onto flexible polyethylene terephthalate (PET)/ indium tin oxide (ITO) film using electron beam evaporation method. In order to deeply characterize all films, scanning electron microscopy‐energy dispersive X‐ray spectroscopy (SEM‐EDS) and electrochemical impedance spectroscopy (EIS) techniques were used. The counter electrode effect on plasma modified WO₃ nano hybrids‐based electrochromic devices (ECDs) was evaluated. By incorporating flexible vanadium pentoxide (V₂O₅) film as counter electrode, complementary ECDs were constructed through combining the hybrid flexible films (WO₃‐PEDOT, WO₃‐PFu) as working electrodes, which exhibit highly efficient electrochromic performance with low voltage operation. Especially, WO₃‐PEDOT/V₂O₅‐based ECD owns a high optical modulation of 61.5 % at 750 nm driven by −1.0 V (coloration) and +1 V (bleaching) with fast response times (coloration time: 13.58 s, bleaching time: 8.07 s) and a high coloration efficiency of 527 cm² C⁻¹. This study can supply useful and efficient avenue for designing flexible complementary electrochromic device for energy‐saving flexible electronics.     

Poly(ProDOT‐Et2): A High‐Contrast,High‐Coloration Efficiency Electrochromic Polymer

The synthesis and electrochemical polymerization of 3,3‐diethyl‐3,4‐dihydro‐2H‐thieno‐[3,4‐b][1,4]dioxepine (ProDOT‐Et₂) was performed resulting in a stable electrochromic polymer capable of switching between an absorbing blue neutral state and a highly transmissive sky‐blue oxidized state in sub‐second time frames. High optical switching contrast ratios (up to 75% at λ_max) and high composite coloration efficiencies (505 cm²/C) were measured.     

A new green-to-transmissive polymer with electroactive poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) as an interface layer for achieving high-performance electrochromic device

A new neutral green electrochromic (EC) polymer, namely poly(5,8-bis(2,3-dihydro[3,4-B][1,4]dioxin-5-yl)-2,3-dual(4-(hexadecyloxy) phenyl) quinoxaline) (PBOPEQ) was designed and synthesized. PBOPEQ-poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) film was further prepared by electrochemical polymerization on the PEDOT:PSS modified indium tin oxide (ITO) electrode. Scanning electron microscopy images and ultrasonic experiment indicate that PBOPEQ-PEDOT:PSS film shows better film-forming ability and stronger interface adhesive with ITO electrode compared to that of PBOPEQ film. It is worth mentioning that PBOPEQ-PEDOT:PSS film presents more reversible redox characteristic, better optical contrast (~40%) and coloration efficiency (~230 cm² C⁻¹) at 678 nm, excellent EC stability and memory property (36 hr), which should be ascribed to that the electroactive PEDOT:PSS layer facilitates the charge transfer process and enhances the ion doping/dedoping properties. EC device based on PBOPEQ-PEDOT:PSS film exhibits superior integrated performance such as reversible color change from green to transmissive, optical contrast of 41.0% and switching time less than 1 s. Accordingly, PBOPEQ-PEDOT:PSS is an excellent EC material when combined with electroactive PEDOT:PSS interface layer for achieving high performance device, which shows potential applications in displays, electronic papers, and tags.     

A soluble and multichromic conducting polythiophene derivative

A new soluble polythiophene derivative was synthesized by both chemical and electrochemical oxidative polymerization of 1-4-nitrophenyl-2,5-di(2-thienyl)-1H-pyrrole (SNSNO₂). Chemical method produces a polymer which is completely soluble in organic solvents. The structures of both the monomer and the soluble polymer were elucidated by ¹H and ¹³C-NMR and FTIR. The average molecular weight has been determined by GPC to be Mn = 6.3 × 10³ for the chemically synthesized polymer. P(SNSNO₂) was also synthesized via potentiostatic electrochemical polymerization. Characterizations of the resulting polymer were performed by cyclic voltammetry CV, FTIR and UV-Vis spectroscopy. Four-probe technique was used to measure the conductivities of the samples. Moreover, the spectroelectrochemical and electrochromic properties of the polymer film were investigated. In addition, dual type polymer electrochromic devices ECDs based on P(SNSNO₂) with poly3,4-ethylenedioxythiophene (PEDOT) were constructed. Spectroelectrochemistry, electrochromic switching and open circuit stability of the devices were studied. They were found to have good switching times, reasonable contrasts and optical memories.     

Soluble alkyl substituted poly(3,4‐propylenedioxyselenophene)s: A new platform for optoelectronic materials

Optical and electrochemical properties of regiosymmetric and soluble alkylenedioxyselenophene‐based electrochromic polymers, namely poly(3,3‐dibutyl‐3,4‐dihydro‐2H‐selenopheno[3,4‐b][1,4]dioxephine) (PProDOS‐C₄), poly(3,3‐dihexyl‐3,4‐dihydro‐2H‐selenopheno[3,4‐b][1,4]dioxephine) (PProDOS‐C₆), and poly(3,3‐didecyl‐3,4‐dihydro‐2H‐selenopheno[3,4‐b][1,4]dioxephine) (PProDOS‐C₁₀), are highlighted. It is noted that these unique polymers have low bandgaps (1.57–1.65 eV), and they are exceptionally stable under ambient atmospheric conditions. Polymer films retained 82–97% of their electroactivity after 5000 cycles. The percent transmittance of PProDOS‐C_n (n = 4, 6, 10) films found to be between 55 and 59%. Furthermore, these novel soluble PProDOS‐C_n polymers showed electrochromic behavior: a color change form pure blue to highly transparent state in a low switching time (1.0 s) during oxidation with high coloration efficiencies (328–864 cm² C^?1) when compared to their thiophene analogues. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Spectroelectrochemical Studies on Silicate Sol‐Gel Matrix‐supported Sub‐10 nm Prussian Blue Nanostructures‐based Electrochromic Device

In this study, spectroelectrochemical (SPE) studies to monitor the electrochromic properties of electrochemically synthesized sub‐10 nm sized Prussian blue (PB) nanostructures (NSs) are employed. At the beginning the dark blue coloured device, shifts reversibly between translucent and dark‐blue while applying an applied bias between +1 to ?1 V with an opposite polarization. Amine functionalized silicate sol‐gel matrix (SSG) is used as a solid support and stabilizer for electrodepositing highly uniform sub‐10 nm PB NSs. The SSG's film thickness is suitably optimized through suitable controlled experiments. It is found that the SPE behaviour of sub‐10 nm sized PB NSs, suitably followed a colour modulation of PB into Prussian white (PW) and vice‐versa. SPE studies are used to investigate the redox switching between the PB and PW and which are responsible for an electrochromic function of a fabricated electrochromic device (ECD). Fabricated ECD has demonstrated an optical modulation at 680 nm with the moderate coloration efficiency of 115.8 cm²/C. Present study validates the SPE feature of sub‐10 nm PB NSs as an active electrochromic nanomaterial and demonstrating the applicability of SPE technique to investigate the variety of electrochromic nanomaterials, with consequences in both spectral and electrochemically active nanomaterials for electrochromic device applications.     

A new soluble conducting polymer and its electrochromic devices

A new polythiophene derivative was synthesized by both chemical and electrochemical oxidative polymerization of 1‐(1‐phenylethyl)‐2,5‐di(2‐thienyl)‐1H‐pyrrole (PETPy). Of which the chemical method produces a polymer that is completely soluble in organic solvents. The structures of both the monomer and the soluble polymer were elucidated by nuclear magnetic resonance (¹H and ¹³C NMR) and Fourier transform infrared (FTIR) spectroscopy. The average molecular weight has been determined by gel permeation chromatography to be M_n = 3.29 × 10³ for the chemically synthesized polymer. Polymer of PETPy was synthesized via potentiostatic electrochemical polymerization in acetonitrile (AN)/NaClO₄/LiClO₄ (0.1 M) solvent–electrolyte couple. Characterizations of the resulting polymer were performed by cyclic voltammetry, FTIR, scanning electron microscopy, and UV–vis spectroscopy. Four‐probe technique was used to measure the conductivities of the samples. Moreover, the spectroelectrochemical and electrochromic properties of the polymer films were investigated. In addition, dual‐type polymer electrochromic devices based on P(PETPy) with poly(3,4‐ethylenedioxythiophene) were constructed. Spectroelectrochemistry, electrochromic switching, and open circuit stability of the devices were studied. They were found to have good switching times, reasonable contrasts, and optical memories. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2215–2225, 2006     

Plasma Modified V2O5/PEDOT Hybrid Based Flexible Electrochromic Devices

Vanadium oxide/poly (3,4‐ ethylenedioxythiophene)(V₂O₅‐PEDOT) hybrid materials were prepared in a rotating quartz plasma reactor via capacitively coupled radio frequency (RF 13.56 MHz) plasma. Thin films of V₂O₅‐PEDOT hybrid and V₂O₅ were obtained by electron beam evaporation technique onto flexible PET substrate for electrochromic devices (ECDs) applications. As a counter electrode, both RF magnetron sputtered MoO₃ onto ITO coated PET and only ITO coated PET electrodes were used. Characterizations of the films were carried out via using scanning electron microscopy‐energy dispersive X‐ray spectroscopy (SEM‐EDX) and X‐ray diffraction (XRD). Hybrid ECDs results showed that synergistic effect depending on improved stability between V₂O₅ and PEDOT. As a result, we developed all solid complementary electrochromic devices including V₂O₅, V₂O₅‐PEDOT and MoO₃ films. The electrochromic device characteristics such as electrochromic contrast, coloration efficiency, switching time were calculated from optical and electrochemical measurements. The highest coloration efficiency and optical contrast were obtained as 53 cm²/C and 17 % for V₂O₅‐PEDOT/MoO₃‐based ECD.     

Thieno[3,2‐b]Thiophene End‐Capped all‐Sulfur Analog of 3,4‐Ethylenedioxythiophene and its Eletrosynthesized Polymer: Is Distorted Conformation Not Suitable for Electrochromism?

By employing planar thieno[3,2‐b]thiophene (TT) as end‐capped units and famous 3,4‐ethylenedioxythiophene (EDOT) or its all‐sulfur analog 3,4‐ethylenedithiathiophene (EDTT) as cores, two conjugated oligomer, TT‐EDOT‐TT and TT‐EDTT‐TT, have been synthesized and electropolymerized into electrochromic polymer films, P(TT‐EDOT‐TT) and P(TT‐EDTT‐TT), respectively. Due to strongly noncovalent inter/intramolecular interactions from S? S attraction of TT‐EDTT‐TT, it has twisted molecular configuration in contrast to planar TT‐EDOT‐TT. Spectroscopic, electrochemical, morphological as well as theoretical calculation studies of these oligomers or polymers were carried out to reveal the significant influence of such molecular geometry on their physicochemical and optoelectronic properties. According to electrochromic kinetics, P(TT‐EDTT‐TT) presented preferable electrochromic behavior such as the higher optical contrast (70.8%), favorable coloration efficiency (331.3 cm² C^?1) and fast response time (0.72 s). This research will help us deeply understand the effect of spatial organization of precursor molecules on the properties of electrochromic polymers and provides a promising strategy to develop high‐performance electrochromic materials. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 1041–1048     

Synthesis and electrochromism of novel organosoluble polyarylates bearing triphenylamine moieties

A series of novel aromatic polyarylates with triphenylamine units in the main chain and as the pendent group were prepared from the dicarboxylic acid monomer, N,N‐bis(4‐carboxyphenyl)‐N′, N′‐diphenyl‐1,4‐phenylenediamine (1), and various bisphenols. These polyarylates were amorphous and readily soluble in common organic solvents. They had excellent levels of thermal stability associated with moderately high T_g values (182–263 °C). These polymers exhibited strong UV–vis absorption bands at 357–360 nm in toluene solution and the photoluminescence spectra showed maximum bands around 493–503 nm in the green region. The hole‐transporting and electrochromic properties were examined by electrochemical and spectroelectrochemical methods. Cyclic voltammograms of the polyarylates exhibited two reversible oxidation redox couples in acetonitrile solution at E_onset 0.77–0.79 V and 1.12–1.14 V, respectively. The typical polymer 3b film revealed good stability of electrochromic characteristics, with color change from colorless to green and blue at applied potentials ranging from 0.00 to 1.24 V. These anodically polymeric electrochromic materials not only showed excellent reversible electrochromic stability with good green coloration efficiency (CE = 159 cm²/C) and blue coloration efficiency (CE = 154 cm²/C) but also exhibited high contrast of optical transmittance change (ΔT%), 54% in 895 nm for green color and up to 84% in 595 nm for blue color. After over 100 cyclic switches, the polymer films still exhibited excellent stability of electrochromic characteristics. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2004–2014, 2007     

Synthesis and Electrochromic Properties of Star‐Shaped Oligomers with Phenyl Cores

A series of star‐shaped conjugated oligomers, 1,3,5‐tri(2′‐thienyl) benzene (3TB), 1,3,5‐tri(3′,4′‐ethylenedioxythienyl) benzene (3EB), 1,3,5‐tri[5′,2“‐(3”,4“‐ethylenedioxy‐thienyl)‐2′‐thienyl] benzene (3ETB), and 1,3,5‐tri[5′,2”‐(3“,4”‐ethylenedioxy‐thienyl)‐2′‐thienyl]‐4‐(3′,4′‐ethylenedioxythienyl)benzene (3TB‐4EDOT), were synthesized. The star‐shaped polymer, poly(1,3,5‐tri[5′,2“‐(3”,4“‐ethylenedioxythineyl)‐2′‐thienyl]benzene) (P3ETB), was also prepared. The electrochemical and electrochromic properties of these conjugated oligomers and polymer were investigated. These oligomer and polymer films showed reversible, clear color changes upon electrochemical doping and dedoping. The color of the P3ETB film reversibly changed from orange to blue under doping and dedoping. The switching times for doping and dedoping were 1.2 and 0.9 s, respectively.     

Electrosynthesis and electrochromic properties of free‐standing copolymer based on oligo(oxyethylene) cross‐linked 2,2’‐bithiophene and 3,4‐ethylenedioxythiophene

Oligo(oxyethylene) chains cross‐linked 2,2’‐bithiophene (BT‐E5‐BT) has been synthesized successfully. A free‐standing copolymer film based on BT‐E5‐BT and 3,4‐ethylenedioxythiophene (P(BT‐E5‐BT‐co‐EDOT)) has been synthesized by electrochemical polymerization. The electrical conductivity of P(BT‐E5‐BT‐co‐EDOT) copolymer (16 S m^?1) has improved by four orders of magnitude compared to the homopolymer of BT‐E5‐BT (P(BT‐E5‐BT), 5 × 10^?3 S m^?1) at room temperature. Both homopolymer and copolymer films exhibit well‐defined redox and satisfied coloration efficiency. Spectroelectrochemistry studies indicate that the P(BT‐E5‐BT‐co‐EDOT) has a lower band gap in the range of 1.83–1.90 eV and shows more plentiful electrochromic colours (green, blue, purple and salmon pink) compared with the homopolymer P(BT‐E5‐BT). The Copolymer P(BT‐E5‐BT‐co‐EDOT) shows the moderate optical contrast (26% of 480 nm) and coloration efficiency (205.41 cm^?1 C^?2). The copolymer method provides a novel way to fabricate a free‐standing organic electrochromic device. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1583–1592     

Poly(thieno[3,4‐b]‐1,4‐oxathiane) and poly(3,4‐ethylenedioxythiophene‐co‐thieno[3,4‐b]‐1,4‐oxathiane)/poly(styrene sulfonic sodium): Preparation,characterization, and optoelectronic performance

In this work, the asymmetrical analog of 3,4‐ethylenedioxythiophene (EDOT), thieno[3,4‐b]‐1,4‐oxathiane (EOTT), was synthesized and chemically polymerized first in aqueous solution using poly(styrene sulfonic sodium) (PSS) as the polyelectrolyte to yield poly(thieno[3,4‐b]‐1,4‐oxathiane) (PEOTT)/PSS. As‐formed film exhibited low electrical conductivity (～10^?4 S/cm). Alternatively, EOTT together with EDOT (in different molar ratio of 1:1 and 1:5) was copolymerized and the polymer poly(EOTT‐co‐EDOT)/PSS had electrical conductivity of 10^?1 S/cm. After dimethyl sulfoxide (DMSO) treatment, the electrical conductivity was enhanced to 10⁰ S/cm; however, the conductivity of the above homopolymer was reduced (～10^?5 S/cm). Raman spectroscopy was used to interpret conductivity enhancement or reduction after DMSO treatment. The conductivity decrease of PEOTT/PSS compared to poly(EOTT‐co‐EDOT)/PSS may arise from the conformational change of PEOTT backbone from the quasi‐planar to the distorted planar mode induced by PSS^–/PSSH through ionic interaction. Kinetic studies revealed that the copolymer had high coloration efficiencies (375 cm²/C), low switching voltages (?0.8 to +0.6 V), decent contrast ratios (45%), moderate response time (1.0 s), excellent stability, and color persistence. An electrochromic device employing poly(3‐methylthiophene) and poly(EOTT‐co‐EDOT)/PSS as the anode and cathode materials was also studied. From these results, poly(EOTT‐co‐EDOT)/PSS would be a promising candidate material for organic electronics. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2285–2297