Electrochemical Analysis of Conducting Polymers PEDOT:PSS/PVA
- John LaRue, Associate Dean for Student Affairs, University of California Irvine
- Chang-hsiu Chen, Postdoctoral Assistant Specialist, University of California Irvine
Blends of the conducting polymer Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate) (PEDOT:PSS) with Polyvinyl Alcohol (PEDOT:PSS/PVA) have many potential applications including Micro-electro-mechanical Systems (MEMS) and other electronic devices. Acting as the electrical conductor, PEDOT:PSS provides a good mechanism in its electrical applications, but due to its brittle nature, mixtures with PVA provide needed ductility and other mechanical enhancements. Concentrations of PEDOT:PSS at 30 weight percentage in PEDOT:PSS/PVA mixtures have been found to provide optimum mechanical and electrical properties. PEDOT:PSS/PVA films are prepared with a casting method and dried in air for several days. Utilizing Electrochemical Impedance Spectroscopy (EIS) provides an analytical method to investigate electrical properties and corresponding mechanisms. In this study, a Gamry femtostat three-electrode system is used to measure vertical impedance of PEDOT:PSS/PVA films. By using Gamry Echem Analyst, graphical impedance measurements such as Bode, Nyquist, and Phase Angle plots are presented and are also used for circuit diagram fitting to obtain circuit component values. Components approximated thereafter are used in calculations for permittivity, electric modulus, and resistivity. It is also noted that PEDOT:PSS/PVA blended at various temperatures (~25°C - 40°C) results in different electrical properties due to the changing evaporation rate of the solvent. 30 wt% of PEDOT:PSS in a PEDOT:PSS/PVA mixture at room temperature is found to have complex permittivity at 2118 F/m, complex modulus at 3.69∙10-6 m/F, and resistivity values at 1.5∙106 ohms at a 1Hz calculation.