Apparent dependence of conductivity of a conducting polymer on an electric field in a field effect transistor configuration

Abstract

Articles you may be interested inStructure and properties of polymer core-shell systems: Helium ion microscopy and electrical conductivity studies J. Vac. Sci. Technol. B 28, C6P59 (2010); 10.1116/1.3504589 Correlation between morphology and ambipolar transport in organic field-effect transistors Pentacene organic field-effect transistor on metal substrate with spin-coated smoothing layer A curious effect is reported whereby an electric field apparently greatly affects the conductivity of an organic polymer, poly-3,4-ethylenedioxythiophene ͑PEDOT͒, doped to the ''metallic'' conducting regime when it is used in an all-organic polymer field effect transistor configuration. The response time for change in current in the source/drain PEDOT polymer with a change of gate voltage is slow ͑рϳ2 s͒, suggesting that ionic diffusion is involved in the phenomenon. It is suggested that the electric field changes only the conductivity of the lowly conducting polymer matrix, which contains highly conducting islands of PEDOT, thus changing the extent of percolation of electric charge between metallic islands, and thereby affecting the bulk conductivity of the PEDOT source/drain material.

Optimum Design of Organic Electrochemical Type Transistors for Applications in Biochemical Sensing

“…It has been reported [14] that the bulk conductivity in spin-coated PEDOT:PSS thin films can be three orders in magnitude less than the lateral conductivity in the plane of the film. This is because in the perpendicular direction, the PEDOTrich domains are separated by thick barriers formed by PSS lamella, whereas in the parallel direction, within the PEDOTrich lamella, conduction can take place with a thin or no barrier at all by 3D variable-range hopping.…”

“…PVA (∼molecular weight ∼130000) and KCl (250 mM) in the ratio (1:9), baked at 90 • for 4 hours, were used as the solidelectrolyte. Further fabrication details for these solid-state devices are mentioned in [8,14]. In all our devices, the length of the electrolyte, L elec , is equal to the length of gate electrode, L g .…”

Electron-ion interaction in doped conducting polymers

“…The experimental dependence is rather smooth with the gate voltage. [17][18][19][20][21] For this reason, we failed to obtain satisfactory fit of the experimental I͑V͒ characteristics using the derived theoretical dependencies, Eqs. ͑36͒-͑39͒.…”

“…We assume also that z i = z e ͉e͉, i.e., we deal with holes and cations as it take place in the experiments. [17][18][19][20][21] From the requirement of electroneutrality ͓Eq. ͑21͔͒, it follows that satisfies the equation…”

“…It was demonstrated 17,18 that conducting polymers may be used as active elements in a transistor structure. An example is shown in the inset of Fig.…”