PSS Dispersion Research Articles

PEDOT:PSS-based electronic “paper” with high surface-interface and mechanical strength and ultra-long wet-resistant capacity

Organic electrochromic conducting polymers (CPs) are at the forefront of flexible and ultra-thin display electronics. Solution processable poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) exhibits excellent electrical and electrochemical behavior in line with great processability, stability, and other promising properties. However, their uses are limited by the weak mechanical properties, wet instability, as well as inevitable conflicts among different functionalities and structural characteristics, etc. In this study, we designed and fabricated a high-mechanical-strength electronic “paper”, PEDOT:PSS/PEG-UPy film, employed a thermoplastic polyurethane poly(ethylene glycol)-2-amino-5-(2-hydroxyethyl)-6-methylpyrimidin-4-ol (PEG-UPy) using diverse processing (drop coating, spin coating, blade coating and 3D printing) of its “electric ink (E-ink)” from the mechanical mixture of its isopropanol (IPA) solution with aqueous PEDOT:PSS dispersion. Compared to PEDOT:PSS film, the incorporation of supramolecular chain-expanding unit 2-amino-4-hydroxy-6-methylpyrimidine (UPy) into the PEG-UPy molecular backbone resulted into optimized self-supporting (substrate-free) film of PEDOT:PSS/PEG-UPy(10 wt%) which showed great flexibility, enhanced mechanical strength (elongation at break 47.08 %, tensile strength of 19.16 MPa, toughness 7.973 MJ m−3), considerable electrical properties (0.509 S cm−1), desirable physical properties including resistance to abrasion and solvent-wiping, and excellent surface-interface properties (e.g., hardness of 3H, adhesion of level 0, glossiness of 91). Its electrochromic capabilities include an optical contrast (ΔT) value of 67 %, a fast redox reaction (4 s and 3 s, respectively), and a coloring efficiency (722.19 cm2 C−1). Similar to paper, they can be easily tailored or folded into a variety of forms, but have greater advances on dense morphology, flat surface, considerable optical transparency (79.5 %), as well as robust resistance to mechanical damage (in the case of bending, stretching, and folding, etc.), water (immersing > 150 days), and dirt. The combined effect of molecular design of PEG-UPy, abundant hydrogen-bonded cross-linking interaction and “good” solvent effect of IPA to PEDOT:PSS play important roles in this system. This is the first work on solution processable PEDOT:PSS-based electrochromic “paper” being able to meet much comprehensive performance requirements for the application in practical complex working environment.

A PEDOT: PSS/GO fiber microelectrode fabricated by microfluidic spinning for dopamine detection in human serum and PC12 cells.

Rapid and accurate in situ determinationof dopamine is of great significance in the study of neurological diseases. In this work, poly (3,4-ethylenedioxythiophene): poly (styrenesulfonic acid) (PEDOT: PSS)/graphene oxide (GO) fibers were fabricated by an effective method based on microfluidic wet spinning technology. The composite microfibers with stratified and dense arrangement were continuously prepared by injecting PEDOT: PSS and GO dispersion solutions into a microfluidic chip. PEDOT: PSS/GO fiber microelectrodes with high electrochemical activity and enhanced electrochemical oxidation activity of dopamine were constructed by controlling the structure composition of the microfibers with varying flow rate. The fabricated fiber microelectrode had a low detection limit (4.56 nM) and wide detection range (0.01-8.0 µM) for dopamine detection with excellent stability, repeatability, and reproducibility. In addition, the PEDOT: PSS/GO fiber microelectrode prepared was successfully used for the detection of dopamine in human serum and PC12 cells. The strategy for the fabrication of multi-component fiber microelectrodes isa new and effective approach for monitoring the intercellular neurotransmitter dopamine and has highpotential as an implantable neural microelectrode.

Direct Ink writing of high conductive PEDOT:PSS dispersion with an engineered conformation and electronic structure for printed electronic circuits

PEDOT:PSS dispersions with engineered conformation and electronic structure are obtained by controlling polymerization parameters. Outstanding electrical conductivity makes them promising candidates for conductive inks in printed electronic circuits.

Super-resolution fluorescence imaging of PEDOT:PSS films.

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a popular conduction polymer and widely used in organic electronics, bioelectronics and printed electronics. It is believed that PEDOT:PSS has a core-shell colloidal structure dispersed in the formulation. However, the size and surface functional groups of the PEDOT:PSS dispersion and films remain to be visualized. Here, we have introduced the concept of aggregation-induced emission (AIE) to super-resolution imaging for designing the cationic probe TPE-4N+ and accomplished the nanoscale optical visualization of PEDOT:PSS films through reversible electrostatic interactions. Information on the PEDOT:PSS size and surface charge has been successfully collected via super-resolution imaging. The full-width at half-maximum (FWHM) of PSS nanoparticles was observed to be approximately 30-40 nm. The super-resolution fluorescence imaging method can also be used to monitor the PEDOT:PSS film after acid treatment. It was observed that PSS chains were washed away when exposed to concentrated sulfuric acid, which explains why concentrated sulfuric acid treatment greatly improves the conductivity of the PEDOT:PSS film. Super-resolution imaging is promising as an effective method for characterizing PEDOT:PSS films.

3-oxetanylmethanol as additive to PEDOT:PSS for improved conductivity and water-resistance and applications in ink-jet printed electrochemical transistors

3-oxetanylmethanol is used as additive to poly (3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) water dispersions and the properties of thin films, prepared by spin-coating and ink-jet printing, either on glass or flexible polyethylene terephthalate (PET) substrates, are investigated. 1H NMR studies revealed that 3-oxetanylmethanol is reactive within the PEDOT:PSS medium during the film drying step at 120 °C, to form polyether compounds. Chemical cross-linking established through the esterification reaction of pendant hydroxyl groups in polyether chains, resulting from the 3-oxetanylmethanol in situ polymerization, and sulfonate groups from PSS, is also identified by the 1H NMR studies. Spin-cast films prepared from this formulation on either glass or PET exhibited electrical conductivity enhanced by more than two orders of magnitude, when compared to films obtained with the pristine PEDOT:PSS dispersion, reaching maximum values of around 596 and 682 Scm−1 for films on glass and PET, respectively, together with improved water-resistance. Atomic force microscopy and Raman spectroscopic studies, indicating that PEDOT chains are organized in more ordered domains in the films of the oxetane-based formulations, suggest that the polyether compounds modify the PEDOT:PSS phase segregation and promote charge transport across conducting PEDOT segments. Subsequently, improved conductivities and stability were also found for films prepared by high-resolution ink-jet printing of the formulations that led to the most conductive spin coated films. The potential application of the new ink formulations in printed electrodes interfacing aqueous media was assessed by ink-jet printing PEDOT-based electrochemical transistors operating with aqueous KCl electrolyte.

Performance optimisation of n-i-p type CH3NH3PbI3 based perovskite solar cells using SCAPS 1-D device simulation

Perovskite solar cells (PSCs) are emerging photovoltaic technologies with an efficiency of over 25%. PEDOT:PSS is the most commonly used hole transport material in the p-i-n type perovskite solar cell because the PEDOT:PSS dispersion is typically water-based material. Water-free PEDOT:PSS composites are used in the n-i-p architecture. The inverted PEDOT:PSS-based PSCs show 200 mV less open circuit voltage (VOC) as compared to conventional PSCs. Herein, the n-i-p type perovskite solar cell containing PEDOT:PSS as a hole transport layer is adopted to overcome the problem of open circuit voltage loss in an inverted solar cell. The design and analysis of n-i-p based perovskite solar cell is carried out using the 1D-Solar Cell Capacitance Simulator. The solar cell performance is improved by optimising the different parameters of perovskite solar cell. The optimised n-i-p structure solar cell has achieved the best power conversion efficiency of over 18% with 1.27 V open-circuit voltage for 350 nm thickness of the absorber layer. Therefore, the results provide a pathway to overcoming the voltage loss in PEDOT:PSS-based inverted PSCs by adopting a conventional device structure.

Electrospun Electroluminescent CsPbBr3 Fibers as Flexible Perovskite Networks for Light‐Emitting Application

Thin‐film perovskite light‐emitting diodes have gained increasing attention in the last 6 years. With the possibility to process the emitting layer from solution, the way for 1D morphology of the semiconductor for flexible devices is paved. Herein, for the first time single‐step fabrication of CsPbBr3@PVP nanofibers in a customized electrospinning process performed under ambient conditions from a water‐based precursor solution is reported. The water‐based approach allows the incorporation of a conductive polymer into the compound fiber by blending the perovskite precursor ink with commercially available PEDOT:PSS dispersion. The results demonstrate electrospun fiber mats which are stable at ambient conditions for at least 5 months and can be utilized in electroluminescence devices. Photoluminescence studies on the perovskite fibers reveal a blueshift of the emission peak compared to thin films possibly due to the generation of nanocrystals of ≈12 nm by in situ nanocrystal pinning as confirmed by transmission electron microscopy. A proof‐of‐concept electrically pumped light‐emitting device is built with the obtained fiber mat. The perovskite nanofibers offer promising applications in flexible and stretchable optoelectronics.

Comparative Study of PEDOT- and PEDOT:PSS Modified δ-MnO2 Cathodes for Aqueous Zinc Batteries with Enhanced Properties

Chemically synthesized layered manganese dioxide (δ-MnO2) modified by poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) dispersion were used as cathode materials for aqueous Zn-ion batteries (AZIBs). A comparative study of electrochemical properties of cathodes with pristine MnO2 and materials chemically modified by conducting polymers in different forms was performed with cycling voltammetry and galvanostatic charge-discharge curves in Zn2+-containing electrolyte solutions. The results of electrochemical tests indicate the significant improvement in specific capacity of electrodes in the sequence MnO2, MnO2/PEDOT and MnO2/PEDOT:PSS composites. The MnO2/PEDOT:PSS electrode delivered a specific discharge capacity of 278 mAh·g−1 at a current density 0.3 A·g−1 after 100 cycles, whereas for MnO2/PEDOT and MnO2 electrodes the values were 238 and 121 mAh·g−1 (capacity retention is 99%, 99.5% and 89%, respectively). These specific capacity values obtained for manganese dioxide-based cathodes are demonstrating the positive role of intrinsically conducting polymer, especially in case of surface modification of electroactive particles by PEDOT:PSS dispersion.

Laser-induced porous graphene from PEDOT:PSS films for dye-sensitized solar cells

• 3D porous graphene was firstly fabricated from PEDOT:PSS by a laser-scribing method. • Sheet resistance and morphology of LIG can be easily tuned by changing laser power. • LIG shows enhanced photovoltaic performance as a counter electrode for DSSCs. For the emerging laser-induced graphene (LIG) technologies, the exploration of laser irradiation interactions with various polymers and their new applications remains challenging. Herein, we report a novel strategy for the fabrication of 3D porous graphene electrodes from the aqueous PEDOT:PSS dispersion by a 445-nm diode laser in ambient air. By adjusting the laser power, LIG films exhibit a sheet resistance as low as 50 Ω/sq and their morphologies can change from a carbonized surface to a hierarchical porous structure. The dye-sensitized solar cell with a LIG70 counter electrode achieved a power conversion efficiency of 3.66%, which is over four times that of the pristine PEDOT:PSS electrode (0.80%). This work demonstrates the great potential for the application of PEDOT:PSS-based LIG films in photovoltaic devices.

Aqueous-processable conducting polymer/ionic liquid solutions for highly conductive organic conductors

Herein, we study how the introduction of secondary dopants, ionic liquids (ILs) into an aqueous-processable conducting polymer (CP), PEDOT:PSS [poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate)] affects the PEDOT:PSS dispersion states in the solution, based on dynamic light-scattering analysis. We also investigate the electrical characteristics of PEDOT:PSS/IL films that are processed from the composite blends with varied IL concentration. As a result, we found that the addition of ILs causes growths of PEDOT:PSS dispersions, and there is a relationship between IL-induced dispersion growths and electrical conductivity enhancement. This work could provide a basis for achieving outstanding electrical performance from aqueous-processable CPs.

The Effects of Acidic Secondary Dopants to the Electrical Conductivity of PEDOT: PSS Fabrics

Conductive polymers commonly used as fillers to enhance electrical properties of composite’s system. However, the low conductivity performance of conducting polymers, namely poly(3,4-ethylenedioxythiophene): poly (4-styrene sulfonate) (PEDOT: PSS), constrains their utilization in the field of conductive textile technology in inventing an advanced textiles’ fabric. Maintaining the stability of impregnated PEDOT: PSS fabrics at the microscopic level remains doubtful and unclear. Nowadays, researchers are actively pursuing the introduction of secondary dopants into PEDOT: PSS dispersion to overcome this challenge. In this study, a conductive PEDOT: PSS fabric via immersion technique was prepared and its effects on conductivity upon doped-secondarily by two different dopants; hydrochloric (HCl) and p-toluenesulfonic (p-TSA) acids was revealed. The volume percentage (vol.%) of the secondary dopants (1, 3, 5, 7, 9 vol.%) were varied to find the optimal vol.% for getting the great value of conductivity of the doped PEDOT: PSS fabrics. These fabrics were then analyzed by using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR), Electrochemical Impedance Spectroscopy (EIS), and Scanning Electron Microscopy (SEM) to investigate their conductivity performances chemically. It is found that the conductivity values were affected by varying the strength of the acids. It is concluded, that the 7 vol.% and 5 vol.% of HCl and p-TSA, respectively, gave the highest electrical conductivity values of the PEDOT: PSS fabrics. These findings can be used to provide direction and guidance to researchers in advancing the fields of textiles, electronics and advanced materials.

Structural and Morphological Properties of As-Deposited and Heat Treated Blended Graphene Oxide / Poly(3,4-Ethylenedioxythiophene)-Poly(Styrenesulfonate) Thin Films

In this study the as-deposited and heat treated at 423K of conductive blend graphene oxide (GO)/ poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) thin films was prepared with different PEDOT:PSS concentration (0, 0.25, 0.5, 0.75 and 1)w/w on pre-cleaned glass substrate by spin coater. The XRD analysis indicate the existence of the preffered peak (001) of GO around 2θ=8.24° which is domain in all GO/ PEDOT:PSS films characterized for GO, this result approve the good quality of the PEDOT:PSS dispersion in GO, this peak shifted to the lower 2θ with increasing PEDOT:PSS concentration and after annealing process. The scanning electron microscopy (SEM) images and atomic force microscopy (AFM) clearly show the GO flakes and go to disappear with increasing the PEDOT:PSS concentration.

Manufacturing Poly(3,4‐Ethylenedioxythiophene) Electrocatalytic Sheets for Large‐Scale H2O2 Production

AbstractProducing thick films of conducting polymers by a low‐cost manufacturing technique would enable new applications. However, removing huge solvent volume from diluted suspension or dispersion (1–3 wt%) in which conducting polymers are typically obtained is a true manufacturing challenge. In this work, a procedure is proposed to quickly remove water from the conducting polymer poly(3,4‐ethylenedioxythiophene:poly(4‐styrene sulfonate) (PEDOT:PSS) suspension. The PEDOT:PSS suspension is first flocculated with 1 m H2SO4 transforming PEDOT nanoparticles (≈50–500 nm) into soft microparticles. A filtration process inspired by pulp dewatering in a paper machine on a wire mesh with apertures dimension between 60 µm and 0.5 mm leads to thick free‐standing films (≈0.5 mm). Wire mesh clogging that hinders dewatering (known as dead‐end filtration) is overcome by adding to the flocculated PEDOT:PSS dispersion carbon fibers that aggregate and form efficient water channels. Moreover, this enables fast formation of thick layers under simple atmospheric pressure filtration, thus making the process truly scalable. Thick freestanding PEDOT films thus obtained are used as electrocatalysts for efficient reduction of oxygen to hydrogen peroxide, a promising green chemical and fuel. The inhomogeneity of the films does not affect their electrochemical function.

Evaluation of the In Vitro Biocompatibility of PEDOT:Nafion Coatings.

Poly(3,4-ethylenedioxythiophene)-Nafion (PEDOT:Nafion) is emerging as a promising alternative to PEDOT-polystyrene sulfonate (PEDOT:PSS) in organic bioelectronics. However, the biocompatibility of PEDOT:Nafion has not been investigated to date, limiting its deployment toward in vivo applications such as neural recording and stimulation. In the present study, the in vitro cytotoxicity of PEDOT:Nafion coatings, obtained by a water-based PEDOT:Nafion formulation, was evaluated using a primary cell culture of rat fibroblasts. The surface of PEDOT:Nafion coating was characterized by Atomic Force Microscopy (AFM) and water contact angle measurements. Fibroblasts adhesion and morphology was investigated by scanning electron microscopy (SEM) and AFM measurements. Cell proliferation was assessed by fluorescence microscopy, while cell viability was quantified by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT), lactate dehydrogenase (LDH) and neutral red assays. The results showed that PEDOT:Nafion coatings obtained by the water dispersion were not cytotoxic, making the latter a reliable alternative to PEDOT:PSS dispersion, especially in terms of chronic in vivo applications.

Highly Conductive PPy-PEDOT:PSS Hybrid Hydrogel with Superior Biocompatibility for Bioelectronics Application.

Conductive polymer hydrogels (CPHs) hold significant promise in broad applications, such as bioelectronics and energy devices. Hitherto, the development of a facile and scalable synthesis method for CPHs with high electrical conductivity and biocompatibility has still been a challenge. Herein, we demonstrate highly conductive PPy-PEDOT:PSS hybrid hydrogels which are prepared by a simple solution-mixing method. This fabrication method involves the mixing of a pyrrole monomer with a PEDOT:PSS dispersion, followed by in situ chemical oxidative polymerization to form polypyrrole (PPy). The electrostatic interaction between negatively charged PSS and positively charged conjugated PPy facilitates the formation of PPy-PEDOT:PSS hybrid hydrogels. The conductivity of the PPy-PEDOT:PSS hybrid hydrogels is 867 S m-1. The PPy-PEDOT:PSS hybrid hydrogels show excellent biocompatibility. Moreover, the PPy-PEDOT:PSS hybrid hydrogels have a hierarchical porous structure which facilitates the 3D cell culture within the hydrogels. The PPy-PEDOT:PSS hybrid hydrogels exhibit excellent in situ biomolecular detection and real-time cell proliferation monitoring performance, indicating their potential as highly sensitive electrochemical biosensors for bioelectronics applications. Our strategy for the fabrication of CPHs with the electrostatic interaction between the negatively charged conductive polymer and positively charged conductive polymer would provide new opportunities for the design of highly conductive conjugated hydrogels for bioelectronics applications and energy devices.

Highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/nylon 6 nanofiber web treated with repetitive coating cycles and dimethyl sulfoxide multi-step treatment for electronic textiles

Highly conductive nylon 6 nanofiber web was fabricated with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and dimethyl sulfoxide (DMSO) for electronic textiles. To improve electrical conductivity, repeated coating with PEDOT:PSS and multi-step treatment of DMSO was performed. The effects of these treatments on electrical conductivity, surface properties, and chemical structures were investigated. For repetitive coating cycles, pristine PEDOT:PSS dispersion was dropped onto a nylon 6 nanofiber web for between one and four times of coating. For DMSO multi-step treatment, in the one-step treatment, the nanofiber web was repeatedly treated using PEDOT:PSS doped with DMSO. In the two-step treatment, the nanofiber web was repeatedly treated with doped PEDOT:PSS at first and, then, it was immersed in a DMSO bath. As a result, the sheet resistance decreased dramatically as the number of coating cycles increased. When the two-step treatment was applied, the sheet resistance was much lower compared to that of the one-step treatment, and thereby sample PD4-D with the lowest resistance showed 6.56 Ω/sq. As a result, the surface of the nanofiber web was covered with more PEDOT:PSS as the coating cycle was repeated. The PEDOT particles became large and long shapes after the two-step treatment of DMSO. This inferred that the contact area among conducting PEDOT particles increased because insulating PSS was removed by DMSO. In addition, the presence of PEDOT:PSS and nylon 6 was confirmed. This study proved that the simultaneous treatments of repeated coating with PEDOT:PSS and multi-step treatment of DMSO can improve electrical conductivity, and it developed the highly conductive PEDOT:PSS/nylon 6 nanofiber web.

Extraction of PEDOT:PSS/c‐Si Junction Properties by Modeling of Injection‐Dependent Lifetime Measurements Including Depletion Region Modulation

The carrier lifetime of n‐type silicon wafers coated with the conducting polymer PEDOT:PSS as a function of the excess carrier concentration Δp within the wafer is characterized using the quasi‐steady‐state photoconductance (QSSPC) method, and a drastic increase in the measured apparent lifetime τapp with decreasing Δp is observed. The observed increase with the depletion region modulation (DRM) effect is explained, as PEDOT:PSS‐coated p‐type silicon wafers do not show any increase in lifetime toward low injection levels. By modeling the measured τapp(Δp) curves on n‐type silicon including interface recombination as well as the DRM effect, the interface recombination velocity as well as the band bending Ψs within the silicon induced by PEDOT:PSS are able to be extracted. The impact of adding sorbitol to the PEDOT:PSS dispersion on the τapp(Δp) curves is examined, and it is demonstrated that the admixture of sorbitol improves chemical interface passivation but leaves the band bending within the silicon bulk toward the PEDOT:PSS/c‐Si interface unaffected.

Sprayable PEDOT:PSS based spectrally selective coating for solar energy harvesting

A novel spectrally selective coating was developed on stainless substrates using commercially available poly(ethylene-3,4-dioxythiophene):poly (styrene sulfonate), (PEDOT:PSS) polymer for solar energy harvesting applications. An intrinsic (i.e., single) absorber layer concept was used to develop this coating. The as-prepared PEDOT:PSS dispersion was applied on substrates with thickness in the range of 0.1–5.8 μm using an automated spray deposition system, and the effect of thickness on the optical properties was studied in detail. The intrinsic properties of PEDOT:PSS resulted in high absorptance and low emittance, this was ascertained using glass, quartz and KBR pellets. With optimization of coating thickness, the reflectance edge shifted towards higher wavelength and near perfect absorption was obtained over a broad wavelength range leading to very high absorptance. The optimized PEDOT:PSS coating (approximately 5.8 μm thick) deposited on stainless steel substrates exhibited absorptance of 0.967 and emittance of 0.36.

Fabrication of All-Solid Organic Electrochromic Devices on Absorptive Paper Substrates Utilizing a Simplified Lateral Architecture.

Poly(3,4-ethylenedioxythiophene) doped with the polymer anion poly(styrenesulfonate), PEDOT:PSS, is a common electrochromic material used in the preparation of electrochromic devices (ECDs). In this paper, the PEDOT:PSS doped with a solvent was used both as the electrode and the electrochromic functional layer for fabrication of ECDs on absorptive paper surfaces. The doped PEDOT:PSS dispersion was assessed for the film-forming evenness, sheet resistance and conductivity, and the performance of prepared ECDs for their color contrast and switching dynamics. The ECD performance is discussed in relation to the absorptive characteristics of the substrates. The results indicate that it is feasible to prepare ECDs onto absorptive substrates, despite the partial polymer material imbibition into them. The extent of polymer absorption influences the ECD performance: an increased absorption reduces the color contrast but speeds up the color switching. The electrochemical properties of the used solid electrolyte were found to be crucial for functioning of the ECDs. Insufficient ion transport and associated high resistance led to failure of the devices.

Interchain Spacing and Screening Length Modification of PSS Backbone Chains in Zwitterion-Doped Poly(3,4-Ethylenedioxythiophene):Polystyrene Sulfonate

The interchain spacing and screening length modification of deuterated PSS (d-PSS) backbone chains in zwitterion-doped PEDOT:d-PSS were studied as a function of the doping concentration using small angle neutron scattering. Results suggest that the dopant, 3-(N,N-Dimethylmyristylammonio)propanesulfonate (DYMAP), forms worm-like micelle structures in the PEDOT:d-PSS dispersion that grow in size as the doping concentration increases. The interchain spacing between negatively charged d-PSS remains unaffected by DYMAP up to 15 mM doping concentration. However, from 15 to 25 mM doping concentration, the interchain spacing increases due to steric interactions of grown DYMAP worm-like micelles with the d-PSS chains. At 30 mM doping concentration, the interchain distance between negatively charged d-PSS chains is reduced due to the gelation of the PEDOT:d-PSS dispersion caused by the crosslinking between long DYMAP worm-like micelles and d-PSS chains. Meanwhile, the screening length of the neutralized d-PSS segments attached to the PEDOT oligomers increases as the DYMAP concentration increases form 5 to 30 mM due to the neutralization of the negatively charged d-PSS segments by their Coulomb interaction with the cation in DYMAP.