A Versatile Technique for the Fabrication of PEDOT: PSS Films for Organic Solar Cells

Organic solar cells hold the potential of low-cost production as compared to inorganic solar cells, as well as the increase in efficiency. To realize these possibilities, the key is to fabricate most of the functional films in requisite structures via ambient solution-processed techniques. The PEDOT: PSS films, which are commonly used as an anode layer in organic electronic devices, were deposited on large-area ITO glass substrates under optimized conditions. The spin, spray, brush and brush+spray-coating techniques were utilized to examine their suitability in the fabrication of organic solar cells (OSCs). The films were characterized for their morphology, molecular structure, optical and electrical properties and results are compared with the existing data. A smooth and thin films of PEDOT: PSS were obtained by “Spray+Brush” coating method with attractive sheet-conductivity having  potential in fabricating OSCs with different architectures.Key words: Organic solar cells; PEDOT: PSS films; Solution-processed technique

Contribution Towards Ideal Solid Contact Ion-Selective Electrodes: Mechanistic Studies, Optimization, and Characterization

Solid contact (SC) ion-selective electrodes (ISEs) utilizing conductive polymers (CPs) as ion-to-electron transducers are plagued with poor potential stability, sensor-to-sensor standard potential reproducibility, and long equilibration times which hinders their use as minimal calibration or calibration-free sensors for clinical diagnostics. Some imperfections in the SC sensor performance are thought to be due to the presence of an undesired water layer beneath the ion-selective membrane; a result of the unsatisfactory hydrophobicity of the CP layer. The time-dependent change in the redox potential of the CP layer is the other major factor. To address these issues, in this work, the benefits of the implementation of highly hydrophobic CP layers with controlled redox potentials are investigated.ISEs built with PEDOT(PSS) as SC on Au and GC had short equilibration times while those on Pt had sluggish equilibration. These results were among the first to suggest that the substrate electrode|CP interface plays a significant role in the electrochemical behavior of the SC ISE. Due to the hydrophilicity and hydrogel-like properties of PEDOT(PSS), pH ISEs with PEDOT(PSS) as SC showed significant CO2 interference, which limits its use as a universal SC. To minimize the CO2 interference, PEDOT(PSS) was replaced by POT and PEDOT-C14(TPFPhB) as ion-to-electron transducers in SC ISEs. SC ISEs with POT as SC had unacceptable potential reproducibility partly due to the significant light sensitivity of the POT film. However, the performance characteristics of the POT-based sensors were significantly improved through the incorporation of a TCNQ redox couple into the POT film along with adjusting the TCNQ oxidized/reduced ratio. In contrast to the POT-based SC ISEs, electrodes with the superhydrophobic PEDOT-C14(TPFPhB) as SC exhibited short equilibration times, excellent potential stability, and no light sensitivity. In addition, the PEDOT-C14(TPFPhB) film eliminated CO2 interference, which has been experienced with PEDOT(PSS) as SC. Consequently, the pH sensors with PEDOT-C14(TPFPhB) as SC allow accurate pH determination in whole blood samples with fluctuating CO2 levels. In summary, the data collected with PEDOT-C14(TPFPhB)-based SC K+, Na+, and pH sensors suggest that PEDOT-C14(TPFPhB) may be the ideal SC for SC ISEs which may lead to ISEs requiring minimal to no calibration

Hybrid Structure of Stretchable Interconnect for Reliable E-skin Application

This paper presents the methodology for realisation of stretchable interconnects based on hybrid thin film stack of spray-coated conductive polymer PEDOT: PSS and evaporated gold (Au) film. The PEDOT: PSS film, with its properties in electrical conductivity and mechanical softness, serves as a stress release buffer in the layered hybrid structure. With the serpentine-shape design, the stretchable interconnects can accommodate larger deformation in comparison with a straight line. The correlation between interconnects' morphology (i.e. cracks propagation) with their electrical behaviour has been studied through microscope in along with electrical characterisation under external strain. Furthermore, a comparison in failure strain among different serpentine-shaped designs has been studied. Higher level in stretchability of interconnects can be achieved with a larger arc degree in design. The fabricated stretchable interconnects can accommodate significant deformations up to 72% external strain while maintaining electrically conductive

Anisotropic Properties of Fiber-embedded Soft Materials

信州大学博士(学術)・学位論文・平成23年9月30日授与（甲第66号)・ZHOU JIANThesisZHOU JIAN. Anisotropic Properties of Fiber-embedded Soft Materials. 信州大学, 2011,117p, 博士論文doctoral thesi

Improving the power performance of urine-fed microbial fuel cells using PEDOT-PSS modified anodes

© 2020 The Authors The need for improving the energy harvesting from Microbial Fuel Cells (MFCs) has boosted the design of new materials in order to increase the power performance of this technology and facilitate its practical application. According to this approach, in this work different poly(3,4-ethylenedioxythiophene)-polystyrenesulfonate (PEDOT-PSS) modified electrodes have been synthesised and evaluated as anodes in urine-fed MFCs. The electrochemical synthesis of PEDOT-PSS was performed by potentiostatic step experiments from aqueous solution at a fixed potential of 1.80 V (vs. a reversible hydrogen electrode) for different times: 30, 60, 120 and 240 s. Compared with other methods, this technique allowed us not only to reduce the processing time of the electrodes but also better control of the chemical composition of the deposited polymer and therefore, obtain more efficient polymer films. All modified anodes outperformed the maximum power output by MFCs working with the bare carbon veil electrode but the maximum value was observed when MFCs were working with the PEDOT-PSS based anode obtained after 30 s of electropolymerisation (535.1 µW). This value was 24.3% higher than using the bare carbon veil electrode. Moreover, the functionality of the PEDOT-PSS anodes was reported over 90 days working in continuous mode

Influence of surface structure and morphology of PEDOT: PSS on its optical and electrophysical characteristics

This paper presents the results of a study of the effect of modification of the structure of the PEDOT: PSS polymer with hole conductivity on the optical and electrophysical properties of an organic solar cell. It was found that the modification of a polymer film with ethyl and isopropyl alcohols leads to a change in the morphology and roughness of the film surface. It has been determined that annealing of films in alcohol vapor promotes the formation of more uniform films. It is shown that upon modification of the PEDOT: PSS film in alcohol vapor the absorption spectrum shifts the absorption maximum of PEDOT to the short-wavelength region of the spectrum, the absorption of the aromatic PSS fragment decrease. X-ray phase analysis showed that after surface modification with alcohol vapor, the PEDOT and PSS chains change their structure. It is shown that the structural features of the surface morphology of PEDOT: PSS affect the electrophysical parameters of the films, such as the effective extraction rate and the effective time of flight of charge carriers. It was found that the modification of the surface of the PEDOT: PSS film leads to an improvement in the electrical transport properties of the films