Direct Measurement of Ion Mobility in a Conducting Polymer

Abstract

Using planar junctions between the conducting polymer PEDOT:PSS and various electrolytes, it is possible to inject common ions and directly observe their transit through the film. The 1D geometry of the experiment allows a straightforward estimate of the ion drift mobilities.

Protonic transistors from thin reflectin films

“…13,14,21 We therefore extracted the conductivity from the transistors' I SD vs. V SD curves and used a linear fit of the dependence of this conductivity on V GS to calculate the corresponding proton mobilities. 13,14,21 The average calculated value of µ H+ = 7.7 (±2.1) × 10 −3 cm 2 V −1 s −1 for thin reflectin films was similar to the previously reported values of ∼7.3 × 10 −3 cm 2 V −1 s −1 for thick reflectin films, 21 ∼3 × 10 −3 cm 2 V −1 s −1 for dilute acids, 23 ∼3.9 × 10 −3 cm 2 V −1 s −1 for poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films, 24 and ∼4.9 × 10 −3 cm 2 V −1 s −1 for maleic chitosan nanofibers. 14 We used the calculated mobilities and conductivities to evaluate the proton charge carrier density of the thin reflectin films according to established procedures.…”

“…We investigated the electrical properties of the reflectin films by recording current (I) as a function of voltage (V) at a relative humidity of 90%. 24 The I-V characteristics of a typical reflectinbased device, when contacted with palladium electrodes, are shown in Fig 3. This 0.24 µm-thick device featured a low current density of 0.7 × 10 −2 A/cm 2 at 1.5 V, consistent with previous findings for ∼1 to ∼2 µm-thick reflectin films contacted with proton-blocking electrodes. 21 Subsequently, we converted the device's electron-conducting Pd contacts into proton-injecting PdH x contacts via exposure to hydrogen gas in situ (Fig.…”

Long‐Range Proton Conduction across Free‐Standing Serum Albumin Mats

“…In these devices, the most‐used materials are inorganic oxides,12 metal‐organic frameworks,13 solid acid membranes,14 ionic crystals,15 and polymeric membranes, where the most common example is Nafion 16. Several organic semiconductors have been also shown to have the ability to conduct protons, which enables them to support parallel proton and electron conductivity 17, 18, 19, 20. In recent years several bioorganic materials have been also proposed for protonic devices, such as polysaccharide derivatives and melanin pigment 21, 22, 23, 24, 25.…”

Understanding volumetric capacitance in conducting polymers

“…This is justified by the fact that the Au/PEDOT:PSS contact is ohmic, as expected by the high degree of doping of the polymer, 14 and supported by the fact that output curves of PEDOT:PSS OECTs with Au contacts are linear. 5 At the same time, PEDOT:PSS films processed from solution are known to hydrate extensively and support high drift mobilities for small metal ions, 15 so the assumption of barrier-less ion injection is also justified. Note that this might not be the case in some electrochemically polymerized films such as polypyrrole, in which a high degree of crosslinking might hinder facile ion injection.…”