Electrical Conductivity Of PEDOT Research Articles

Investigations on Impact of YSZ Nanoparticles on Morphology & Electrical conductivity of PEDOT: PSS

Conductive polymer nanocomposites, which combine the flexibility and conductivity of polymers with the unique properties of nanofillers, have generated interest in various fields such as energy storage, sensors, coatings, and corrosion protection. This study discusses the effect of Yttria-stabilized zirconium nanoparticles (YSZ NPs) on the morphology and electrical conductivity of poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonate) (PEDOT: PSS). Thin films of PEDOT: PSS and PEDOT: PSS: YSZ were fabricated using spin coating technique. FTIR and XRD characterizations confirmed the interaction between YSZ nanoparticles and the PEDOT: PSS matrix, leading to changes in chemical morphology and film crystallinity. The investigation of the current-voltage (I-V) relationship showed improved electrical conductivity in PEDOT: PSS films with the addition of YSZ nanoparticles, with respective conductivities of 0.028×10−6 S cm−1 and 0.0885×10−4 S cm−1 for pristine and YSZ-containing films. Additionally, the sensing properties of the PEDOT: PSS: YSZ film in detecting organic vapours were studied. These findings suggest that these conducting polymer nanocomposite thin films could potentially be used as electrolyte components in battery cells, supercapacitors, and fuel cells, as well as serve as sensors for certain organic vapours.

Effect of Film Morphology on Electrical Conductivity of PEDOT:PSS.

Commercially available formulations of the popular conductive polymer, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) are aqueous dispersions that require the addition of secondary dopants such as dimethyl sulphoxide (DMSO) or ethylene glycol (EG) for fabricated films to have the desired levels of conductivity. CleviosTM F HC Solar, a formulation of PEDOT:PSS produced by Heraeus, GmbH, achieves over 500 S/cm without these secondary dopants. This work studies whether secondary dopants such as DMSO have any additional effect on this type of PEDOT:PSS. The temperature dependencies of the conductivity of F HC Solar spin-coated thin films measured using a four-probe method seem to exhibit different charge transport properties compared with secondary doped PH1000. Observations made using atomic force microscopy (AFM) show that different concentrations of DMSO affect the orientation of the PEDOT domains in the thin film. These morphological changes cause room temperature conductivity to reduce from 640 S/cm in pristine films to as low as 555 S/cm after adding 7 wt% of DMSO along the film. Such tuning may prove useful in future applications of PEDOT:PSS, such as nanoprobes, transistors and hybrid solar cells.

An Electrically Resistive Switching Nonvolatile Memory System Based on PEDOT:PSS

The current density–voltage (J–V) curves of poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) are examined at room temperature, which reveal nonlinear behavior and hysteresis loop‐like patterns. Herein, the potential of the material for nonvolatile applications requiring resistive random access memory (ReRAM) is demonstrated. The resistive switching effect is explained using a Schottky barrier and the space‐charge‐limited conduction model. Additionally, dielectric and electrical characteristics are analyzed in the frequency range from 20 Hz to 10 MHz. The impedance, electric modulus, dielectric loss tangent, and AC conductivity are explored through On‐ and Off‐states of resistive switching. A modified Debye function and Jonscher's power law are used for data fitting. The resistive switching memory behavior of PEDOT:PSS are studied using J–V and chemical impedance spectroscopy (CIS) measurements. The Cu/PEDOT:PSS/Cu sandwich‐type devices show bipolar switching behavior, and an equivalent circuit model based on the impedance spectra is proposed to describe the CIS response in both states. The switching process is attributed to the electrical‐field‐induced effect of dipolar reorientation on the electrical conductivity of PEDOT:PSS at grain boundaries.

Incorporation of carbon quantum dots with PEDOT:PSS for high-performance inverted organic solar cells

Inverted organic solar cells (iOSCs) have attracted considerable attention because of their ease of fabrication and suitability for roll-to-roll processing. Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), with multiple favorable properties, is the most actively studied hole-transporting layer (HTL) material. However, the pristine state of PEDOT:PSS is limited by its inefficient, poor, and inhomogeneous conductivity. Herein, we demonstrate strategies to enhance the performance of iOSC devices by introducing carbon quantum dots (CQDs), which have controllable conductivity and band edges, into the PEDOT:PSS HTL. This is considered to be an efficient route for modifying the intrinsic properties and electrical conductivity of PEDOT:PSS. The CQDs were first synthesized through a microwave-assisted process by employing eco-friendly and low-cost material sources. By optimizing the ratio of CQDs incorporated into PEDOT:PSS (PH-G0.05), an iOSC with a remarkable enhancement of 3.90% in power conversion efficiency, was obtained. Using PH-G0.05 HTL helped to improve the contact quality and assisted the hole extraction/transport ability at the photoactive/top Ag anode interface with high electrical conductivity (2.80 S cm–1), good surface morphology (RMS = 7.34 nm), and suitable work function (4.78 eV). Our efforts to develop a solution process for CQDs-incorporated PEDOT:PSS HTLs shows considerable promise for the potential replacement of vacuum-based methods in iOSC applications.

Influence of relative humidity on the structure, swelling and electrical conductivity of PEDOT:PSS fibers

PEDOT:PSS is a conducting polymer with a wide variety of applications in the field of organic electronics. Over the past few years our group has developed PEDOT:PSS fibers with high electrical conductivity and robust mechanical properties, and we have observed changes in their properties that seemed to stem from seasonal changes in atmospheric relative humidity. In this work, we report the influence of relative humidity on the swelling, electrical conductivity and structure of wet-spun PEDOT:PSS fibers. The diameter of the fibers linearly increased with relative humidity up to the 70–80% range where the increase became exponential. The electrical conductivity reversibly decreased with increasing relative humidity with a similar linear and then exponential behavior. Additionally, an irreversible decrease (aging) in electrical conductivity was also observed. To gain more insight into the structural origin of these changes, wide angle x-ray scattering of the PEDOT:PSS fibers were gathered at different relative humidities in the 10–90% range so that the changes in structure could be observed in situ. On one hand, the lamella stacking distance of PEDOT and PSS chains increased linearly up to the 70–80% relative humidity range where the increase became exponential. On the other hand, the π-π stacking distance between PEDOT chains remained unaltered. We found that the changes in the lamella stacking distance were closely correlated to the changes observed for the diameter and electrical conductivity.

Ultrasound‐Responsive Composited Conductive Silk Conduits for Peripheral Nerve Regeneration

Peripheral nerve injuries are challenging to repair clinically due to their limited regenerative capacity. Herein, a novel poly(3,4‐ethylenedioxythiophene):poly(4‐styrene sulfonate) (PEDOT:PSS) composited conductive silk conduit with ultrasound (US)‐triggered active release for peripheral nerve regeneration is presented. The conduit is composed of silk fibroin inverse opal tubular scaffolds and the secondary hydrogel filler that contains thermosensitive material (poly(N‐isopropylacrylamide), PNIPAM), PEDOT:PSS, and nerve growth factor (NGF). Benefiting from the integration of these functional materials and active factors, the silk fibroin conduits show excellent biocompatibility, flexibility, conductivity, and bioactivity. In particular, owing to the thermal effect of US and the temperature responsiveness of PNIPAM, the secondary filling hydrogel undergoes volume shrinkage upon US triggering, allowing the responsive NGF release. Besides, the electrical conductivity of PEDOT:PSS has been affirmed to promote neuron and axon outgrowth. Through in vivo experiments, the synergistic effect of PEDOT:PSS and US‐triggered delivery of NGF on accelerating injured nerve repair are demonstrated. These results reveal the practical value of the proposed intelligent conductive silk conduits with US responsiveness for nerve regeneration in preclinical studies.

One-step post-treatment with amphoteric salt for simultaneous improvement of Seebeck coefficient and electrical conductivity of PEDOT: PSS thermoelectric films

Continuous acid-base treatment can achieve high thermoelectric performance for PEDOT:PSS film, but multiple surface treatments damage samples easily, lowering yield rates as well as increasing preparation costs, preventing its commercialization. To this end, we present an amphoteric salt-based post-treatment strategy for optimizing the charge transport properties and doping levels of PEDOT:PSS films, thereby achieving high electrical conductivity (σ) and Seebeck coefficient (S) simultaneously. As a result, the optimal PEDOT:PSS thermoelectric film delivers a σ of 1462 S·cm−1 and a S of 26.2 μV·K−1, thus achieving a power factor (PF) of 100.4 μW·m−1·K−2, which is significantly higher than pristine specimens with a PF lower than 0.1 μW·m−1·K−2.

Conductive organic electrodes for flexible electronic devices

The paper reports on a novel process flow to manufacture conductive organic electrodes from highly conductive doped PEDOT:PSS polymer films that can be patterned and display a good adhesion to oxidized Si wafers as well as to flexible substrates, such as Mylar. Among other results, it is shown that multiple depositions of PEDOT:PSS increase the electrical conductivity by more than two orders of magnitude without increasing the film thickness of PEDOT:PSS significantly. An exponential dependence between sheet resistance and the number of PEDOT:PSS coatings has been found. The electrical conductivity of PEDOT:PSS can be increased by another two orders of magnitude doping with Cu nanoparticles when coated on the surface of a soft-baked PEDOT:PSS film. It is found, however, that both kinds of conductivity enhancement are not additive. Adhesion of PEDOT:PSS to oxidized Si wafers and BoPET (Mylar) has been ensured by applying an oxygen plasma cleaning step before spin coating. The manufactured high-conductivity PEDOT:PSS film can be patterned using a sacrificial metal layer with subsequent etching of PEDOT:PSS in oxygen plasma, followed by the removal of the patterned segments of the sacrificial metal layer in an aqueous acid solution.

Improving the Conductivity of the PEDOT:PSS Layers in Photovoltaic Cells Based on Organometallic Halide Perovskites.

Among conductive polymers, PEDOT films find the widest application in electronics. For photovoltaic applications, studies of their optical properties, stability, and electrical conductivity are of greatest interest. However, the PEDOT:PSS transport layers, when used in photovoltaic cells, have a high electrical resistance, which prevents solar cells from increasing their efficiency. One of the promising ways to improve their electrical properties is the use of composite materials based on them, in which the conductivity can be increased by introducing various additives. In this work, conductive polymer films PEDOT:PSS (poly (3,4-ethylenedioxythiophene):polystyrene sulfonate acid) doped with a number of amines (Pentylamine, Octylamine, Diethylamine, Aniline with carbon nanotubes) were obtained and studied. It is shown that, depending on the concentration of dopants, the electrical conductivity of PEDOT:PSS films can be significantly improved. In this case, the light transmission of the films practically does not change. The process of improving the conductivity by treating the surface of the finished film with amines, followed by heat treatment, was studied. It is assumed that the improvement in conductivity is the result of the self-assembly of monolayers of organic molecules on the surface of the PEDOT:PSS film leading to its p-doping due to intermolecular interaction.

Photovoltaic Device Application of a Hydroquinone-Modified Conductive Polymer and Dual-Functional Molecular Si Surface Passivation Technology.

In the last decades, the conductive polymer PEDOT:PSS has been introduced in Si-based hybrid solar cells, gaining noticeable research interest and being considered a promising candidate for next generation solar cells which can achieve both of low manufacturing cost and high power conversion efficiency. This study succeeded in improving the electrical conductivity of PEDOT:PSS to 937 S/cm through a simple process of adding hydroquinone (HQ) to the pristine PEDOT:PSS solution. The results also showed that the addition of HQ to PEDOT:PSS(HQ-PEDOT:PSS) could not only dramatically improve the conductivity but also well-sustain the work function characteristics of PEDOT:PSS by promoting the formation of more continuous conductive-PEDOT channels without removing the insulating PSS. In this report, we reveal that the application of the HQ-PEDOT:PSS to the Si/PEDOT:PSS HSC could significantly improve the short-circuit current and open-circuit voltage characteristics to increase the power conversion efficiency of the HSCs compared to the conventional approaches. Moreover, we also treated the Si surface with the organic monomer, benzoquinone (BQ) to (1) passivate the excess Si surface defect states and (2) to improve the properties of the Si/PEDOT:PSS interface. We show that BQ treatment is able to dramatically increase the minority carrier lifetime induced by effective chemical and field-effect passivation in addition to enhancing the wettability of the Si surface with the PEDOT:PSS solution. As a result, the power conversion efficiency was increased by 10.6% by introducing HQ and BQ into the fabrication process of the Si/PEDOT:PSS HSC.

The effect of ethylene glycol post-treatment on the electrical conductivity of PEDOT: PSS thin films

The application of organic conducting polymers such as poly (3,4-ethylene dioxythiophene): poly (4-styrene sulfonate) (PEDOT: PSS) is vastly expanding for the development of advanced and flexible organic electronic devices, such as solar cells, light-emitting diodes, and organic electrochemical transistors (OECTs). Also, PEDOT: PSS can perfectly replace high-cost Indium tin oxide (ITO) thin films. In this study, PEDOT: PSS was synthesized via the chemical oxidative polymerization method. The film formation was carried out through a feasible drop-casting method onto a cleaned glass substrate. To further enhance the conductivity of pristine PEDOT: PSS, the PEDOT: PSS thin films were post-treated with different concentrations (3, 5, and 7% v/v) of ethylene glycol (EG). Based on the electrochemical impedance spectroscopy (EIS) analysis, it was revealed that the post-treated sample had a higher conductivity value compared to the untreated sample (2.48 × 10-4 S/cm), with the highest recorded conductivity value of 2.67 ×10-3 S/cm at 5% v/v of EG. This result corresponds to the previous study, which highlighted that the optimum concentration of EG is 5% v/v to achieve the optimum conductivity value for thin film application. Furthermore, the structural properties of the thin films were characterized using Fourier transform infrared (FTIR) spectroscopy to confirm the presence of PEDOT: PSS and EG in the samples.

Morphological modulation to improve thermoelectric performances of PEDOT:PSS films by DMSO vapor post-treatment

The thermoelectric performance of poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) films are optimized by dimethyl sulfoxide (DMSO) vapor post-treatment on the basis of DMSO addition in PEDOT:PSS solution. Compared with pristine films, the electrical conductivity of PEDOT:PSS with 5% DMSO films is increased by two orders of magnitude. When the PEDOT:PSS with 5% DMSO films are subjected to DMSO vapor post-treatment, the electrical conductivity and Seebeck coefficient are further enhanced. As a result, the power factor of 60 min treated PEDOT:PSS with 5% DMSO films is twice larger than the one without DMSO vapor treatment. Microscopical investigations reveal the morphological evolution of the DMSO vapor treated films. After certain of treating time, quite even and uniformed film morphology is developed, which indicates that film micro-structural order is improved. Through the study of carrier concentration by optical absorption spectra and XPS, it is confirmed that the improvements of thermoelectric performances are attributed to the enhancement of carrier mobility.

Role of the Processing Solvent on the Electrical Conductivity of PEDOT:PSS

AbstractPoly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is one of the most studied conductive polymers, holding great potential in many applications such as thermoelectric generators, solar cells, and memristors. Great efforts have been invested in trying to improve its mechanical and electrical properties and to elucidate the structure–property relationship. In this work, a systematic and quantitative study of the effect of solvent polarity and solution processing on the film structure and conductivity is presented. By using grazing‐incidence wide‐angle X‐ray scattering (GIWAXS) together with atomic force microscopy (AFM), the importance of the quality of the PEDOT crystal packing is highlighted as a key factor to reach improved electrical conductivity, rather than the overall degree of crystallinity. Moreover, the (re)structuring mechanisms occurring during the film formation and film exposure processes are also studied by in situ GIWAXS. Different intermediate precursor stages and different pathways to reach improved crystallinity are reported depending on the used solvent. The structural results are interpreted looking at the solvent nature and the PSS/solvent affinity. With this contribution, a guidance is hoped to be given not only on how to improve the PEDOT:PSS electrical conductivity, but also on how to tune the film structural or electrical property for different applications.

PEDOT:PSS coating on pristine and carbon coated LiFePO4 by one-step process: the study of electrochemical performance

The carbon coating on lithium iron phosphate (LiFePO4) is well known process to improve the electrical conductivity of non-conductive LiFePO4 (LFP). But due to complex process of carbon coating at high temperature, herein, we report study on poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) water soluble conducting polymer coated pristine LFP as well as carbon coated LFP (LFP/C) prepared by simple one step process. PEDOT:PSS coating has played very important role in enhancing the electrochemical performance of Li-ion battery as well as electrical conductivity of LFP and LFP/C samples. The electrical conductivity of PEDOT:PSS coated LiFePO4 samples is increased by many folds (104−108) as compared to pristine and carbon coated LFP. The study reveals that different optimum amount of PEDOT:PSS say 10 wt% and 5 wt% is required for best electrochemical performance of pristine LFP and LFP/C, and samples are designated as LFP-10P and LFP/C-5P respectively. Sample LFP-10P has shown discharge capacity of 140.8 mAh g−1 whereas LFP/C-5P shown 154.6 mAh g−1 at current rate of 0.1C. The same samples have shown highest capacity retention of 92% and 96% respectively after 200 cycles, in their group.

Fabrication of Highly Conductive Porous Cellulose/PEDOT:PSS Nanocomposite Paper via Post-Treatment.

In this paper, we report the fabrication of highly conductive poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS)/cellulose nanofiber (CNF) nanocomposite paper with excellent flexibility through post-treatment with an organic solvent. The post-treated PEDOT:PSS/CNF porous nanocomposite papers showed a lower sulfur content, indicating the removal of residual PSS. The electrical conductivity of PEDOT:PSS/CNF porous nanocomposite paper was increased from 1.05 S/cm to 123.37 S/cm and 106.6 S/cm by post-treatment with dimethyl sulfoxide (DMSO) and ethylene glycol (EG), respectively. These values are outstanding in the development of electrically conductive CNF composites. Additionally, the highly conductive nanocomposite papers showed excellent bending stability during bending tests. Cyclic voltammetry (CV) showed a Faradaic redox reaction and non-Faradaic capacitance due to the redox activity of PEDOT:PSS and large surface area, respectively. Electrochemical energy storage ability was evaluated and results showed that capacitance improved after post-treatment. We believe that the highly conductive PEDOT:PSS/CNF porous nanocomposite papers with excellent flexibility described here are potential candidates for application in porous paper electrodes, flexible energy storage devices, and bioengineering sensors.

Effect of molecular weight distribution of PSSA on electrical conductivity of PEDOT:PSS

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is the most successful conductive polymer. In this study, we investigated the electrical properties of PEDOT:PSS prepared using poly(styrenesulfonic acid) (PSSA) having different molecular weight distributions. Herein PSSA with different molecular weight distributions were successfully polymerized by free radical polymerization and atom-transfer radical polymerization (ATRP). Polydispersity index values of PSSA obtained by the free radical process and ATRP process were 2.3–2.8 and 1.2–1.6 respectively. The electrical conductivity of PEDOT:PSS was enhanced from 376 S cm−1 (prepared using free radical PSSA) to 422 S cm−1 (prepared using ATRP PSSA) when PSSA of Mn 35 000 g mol−1 PSSA was used and was enhanced from 234 S cm−1 (prepared using free radical PSSA) to 325 S cm−1 (prepared using ATRP PSSA) when PSSA of Mn 55 000 g mol−1 was used, by a factor of 15–30%. The greater the regularity of PSSA, the greater the packing density of PEDOT:PSS and consequently, charge carrier density. The improvement of packing density of PEDOT:PSS was confirmed by improvement in crystallinity of PEDOT:PSS by X-ray diffraction (XRD) analysis.

Enhanced electrical properties of poly(3,4-ethylenedioxythiophene:poly(4-styrenesulfonate) using graphene oxide

Abstract Thin film of graphene oxide and PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) is a promising candidate of transparent conductive electrode material for economical thin film devices. In this research, spin coating technique was utilized to fabricate high-performance PEDOT:PSS/GO (graphene oxide) thin films. Graphene oxide sheets were evenly dispersed in aqueous solution of PEDOT:PSS. The solution-processing of PEDOT:PSS/GO was simplified in this experiment to enable economical commercialization of electronic devices. The fabricated PEDOT:PSS/GO thin films have been proven to have outstanding electrical properties. When 5% of graphene oxide was added into the solution, the electrical conductivity of PEDOT:PSS/GO thin film was found to be 90 S/cm, which is an increase of 5 times compared to the conductivity of pristine PEDOT:PSS. This exceptional improvement is attributed to the higher carrier mobility, due to interaction between GO with PEDOT via π→π stacking.

A focus on polystyrene tacticity in synthesized conductive PEDOT:PSS thin films

Poly(3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) is a transparent conductive material and a good candidate for being employed as substitute for indium tin oxide (ITO) in reducing the production costs of organic solar cells. To enhance the performance of organic devices, an improving in the conductivity of PEDOT:PSS is crucial and using the solvent additive rises the electrical conductivity by the optimization of the film morphology. The studies have only focused on the relationship between the electrical conductivity of thin films and the crystallinity of PEDOT, and it is also found that the high conductivity is observed in the highly crystalline samples. This study focused on the effect of tacticity of PS on the conductivity of PEDOT:PSS films. First, atactic and isotactic polystyrenes were sulfonated and the complexes of PEDOT:PSS were synthesized. The N-methylpyrrolidone (NMP), as a secondary dopant, was then added to the complexes and conductivity enhancement was investigated in various annealing times. The obtained films were characterized by atomic force microscopy, X-ray diffraction, four point probe resistivity measurement system, UV–visible spectroscopy, FT-IR, and cyclic voltammetry. The electrical conductivity of PEDOT:iPSS films synthesized by the isotactic polystyrene was ~ 0.68 S/cm and by adding 5 wt% NMP into PEDOT:PSS solution, the conductivity of the annealed thin layers increased more than 10-folds (~ 7.73 S/cm) at an appropriate temperature.

Modification of Optical and Electrical Characteristics of PEDOT:PSS by Umbelliferone Addition: Optical and Electrical Characterization of Umbelliferone Doped PEDOT:PSS for Photovoltaic Applications

Background: In the last 40 years, scientific efforts were focused on the efficiency improvement in organic photovoltaic devices. Bleaching agents were used to absorb UV light and convert it into lower energy radiation appear as potential candidates for further improvements. The present contribution investigated the effect of adding umbelliferone to poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) on its optical and electrical properties. Methods: Characterizations were performed under various umbelliferone concentrations. Fluorescence decay lifetimes were obtained using a MicroTime 200 system (PicoQuant). The UV–vis absorption spectra were obtained with a GE Healthcare Ultrospec 2100 pro Spectrometer. The electrical conductivity measurements as a function of temperature using a cryostat model ARS CS202AE-DMX-1AL. Results: The absorbance increases around 325 nm and decreases in the near infrared s the umbelliferone concentration is increased. It also decreases the absorption in the visible spectrum, concomitantly with a significant increase in the UV region. The electrical conductivity for the umbelliferone doped PEDOT:PSS films display an increase with increasing temperature, but does not follow a linear behavior with the increase of umbelliferone concentration in the films. Conclusion: It was shown that the absorbance displays a redshift in doped samples, while photoluminescence experiments demonstrated that UV light is converted to the visible spectrum more efficiently, which is a desirable feature for photovoltaic devices. Also, the electrical conductivity of PEDOT:PSS is increased for moderate umbelliferone concentrations.

The effect of tannic acids on the electrical conductivity of PEDOT:PSS Films

Conductive poly(ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) films with good transparency and great flexibility are highly demanded in various areas. A facile method is employed to produce conductive films with UV-blocking properties. The direct addition of tannic acids (TAs) powders into PEDOT:PSS aqueous suspension lead to the enhancement of electrical conductivity of TA:PEDOT:PSS (TAPE) films. This improvement owes to the conformation change of the PEDOT chains from benzoid to quinoid configuration. Further investigations revealed the absence of phase separation in the highest conductive TAPE film. TAPE films are smoother and thicker than the pristine PEDOT:PSS film owing to the high density and good solubility of TAs. The absorbance increases with the increase of the TA content in TAPE films. The core levels of oxygen and sulfur atoms in PEDOT and PSS have been studied, which illustrate the composition of TAPE films.