Twisted Nematic Liquid-Crystal-Based Terahertz Phase Shifter using Pristine PEDOT: PSS Transparent Conducting Electrodes

For this study, we demonstrated three different types of twisted nematic (TN) liquid crystal (LC) terahertz (THz) phase shifters using pristine poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT: PSS) thin films as transparent conducting electrodes (TCEs). The transmittance of spin-coated pristine PEDOT: PSS thin film was as high as 92% in the frequency range of 0.2–1.2 THz. This is among the highest reported. Several TN-LC cells were constructed in a comparative study, which confirmed the reliability of pristine PEDOT: PSS as a TCE layer for THz phase shifter applications. The highest phase shift, required root-mean-square (RMS) driving voltage, and threshold voltage achieved by devices tested were 95.2° at 1 THz, 7.2 VRMS, and 0.5 VRMS, respectively. The thickness of the LC layer for the phase shifter was 250 µm, approximately half as thick as previous designs. In addition, the pristine PEDOT: PSS-based TN-LC phase shifter exhibited a figure-of-merit (FOM) value of approximately 6.65 degree·dB−1·V−1. This compared favorably with previously reported homogeneously aligned phase shifters with an FOM of 2.19 degree·dB−1·V−1. Our results indicated that a twisted nematic LC cell with pristine PEDOT: PSS thin films as electrodes is a good combination for a THz phase shifter and wave plates as well as other LC-based THz devices.

The Synergistic Effects of Gold Particles and Dexamethasone on the Electrochemical and Biological Performance of PEDOT Neural Interfaces

Although neural devices have shown efficacy in the treatment of neurodegenerative diseases, their functionality is limited by the inflammatory state and glial scar formation associated with chronic implantation. The aim of this study was to investigate neural electrode performance following functionalization with an anti-inflammatory coating derived from a conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) matrix doped with dexamethasone (Dex) and decorated with Au particles. Pristine PEDOT, PEDOT-Dex and their gold-decorated analogues (PEDOT/Au and PEDOT-Dex/Au) were formulated by electrochemical deposition and characterized with respect to electrode electrochemical properties, surface morphology and biocompatibility towards primary neural cells. Through a process of gold deposition, it was possible to eliminate the initial burst release observed in PEDOT-Dex and maintain a stable, stepwise increase in Dex elution over 7 days. The released amounts of Dex exceeded the concentrations considered as therapeutic for both PEDOT-Dex and PEDOT-Dex/Au. The results clearly indicated that the presence of either Dex or Au particles facilitated the outgrowth of neurites. Finally, it was shown that the application of composite materials, such as PEDOT-Dex/Au, is an efficient way to improve the efficacy of neural interfaces in vitro.

Modified PEDOT by benign preparing N-doped reduced graphene oxide as potential bio-electrode coating material

We have successfully prepared PEDOT/N-rGO by electrodeposition, post-reduction, and doping N atoms with a microorganism to resolve the exfoliation and fragmentation problems of pristine PEDOT.

SILICON NANOPARTICLES/PEDOT–PSS NANOCOMPOSITE AS AN EFFICIENT COUNTER ELECTRODE FOR DYE-SENSITIZED SOLAR CELLS

A novel inorganic/organic nanocomposite film composed of Si nanoparticles (NPs) and poly-(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT–PSS) is obtained from a simple mechanical mixture of Si NPs powder and aqueous PEDOT–PSS solution. Employing this composite film as a counter electrode, dye-sensitized solar cell (DSSC) exhibits an efficiency of 5.7% and a fill factor of 0.51, which are much higher than these of DSSC using pristine PEDOT–PSS electrode (2.9% and 0.25, respectively). The improvements in the photovoltaic performance of the former are primarily derived from improved electrocatalytic performance of the electrode, as evidenced by electrochemical measurements, the composite electrode has lower impedance and higher electrocatalytic activity when in comparison with pristine PEDOT–PSS electrode. These improvements are primarily deriving from the increased electrochemical surface by the addition of Si NPs. The characteristics of Si NPs/PEDOT–PSS composite counter electrode reveal its potential for the use of low-cost and stable Pt-free counter electrode materials. In addition, the results achieved in this work also provide a facile and efficient approach to improve the photovoltaic performance of DSSCs using PEDOT–PSS electrodes.

Interaction of carbon monoxide with PEDOT-PSS/zeolite composite: effect of Si/Al ratio of ZSM-5 zeolite

Composites with poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonic acid), PEDOT-PSS, as the matrix containing ZSM-5 zeolites of various Si/Al ratios in the range of 23-280 at 20% (v/v) were fabricated to investigate the effect of Si/Al ratios on electrical conductivity sensitivity responses towards carbon monoxide (CO). The electrical conductivity responses of PEDOTPSS/ ZSM-5 composites were altered due to the available adsorption sites for CO molecules. The electrical conductivity sensitivity to CO increases with decreasing Si/Al ratios. The composites produce irreversible responses when replacing CO with nitrogen. The addition of ZSM-5 zeolites to the pristine PEDOT-PSS improves the electrical conductivity sensitivity of the composites by enhancing the interaction between PEDOT-PSS and CO gas. The composite of ZSM-5 zeolites with a Si/Al ratio equal to 23 gives the highest electrical conductivity sensitivity toward CO.