Why does the electrical conductivity in PEDOT:PSS decrease with PSS content? A study combining thermoelectric measurements with impedance spectroscopy

Abstract

We have investigated the electrical transport properties of poly(3,4-ethylenedioxythiophen)/poly(4-styrene-sulfonate) (PEDOT:PSS) with PEDOT-to-PSS ratios from 1:1 to 1:30. By combining impedance spectroscopy with thermoelectric measurements, we are able to independently determine the variation of electrical conductivity and charge carrier density with PSS content. We find the charge carrier density to be independent of the PSS content. Using a generalized effective media theory, we show that the electrical conductivity in PEDOT:PSS can be understood as percolation between sites of highly conducting PEDOT:PSS complexes with a conductivity of 2.3 (Xcm) À1 in a matrix of excess PSS with a low conductivity of 10 À3 (X cm) À1 . In addition to the transport properties, the thermoelectric power factors and Seebeck coefficients have been determined. V C 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 50: [976][977][978][979][980][981][982][983] 2012

The Influence of PEDOT to PSS Ratio on the Optical Properties of PEDOT:PSS Thin Solid Films - Insight from Spectroscopic Ellipsometry

“…It is well known that electrical conductivity of PEDOT:PSS thin solid films depends primarily on the content of conductive PEDOT, whereas PSS acts as doping agent and enables hydration in the form of colloidal dispersion, but simultaneously significantly lowers electrical conductivity of the PEDOT:PSS system [2]. It is thus not astonishing that properties of PEDOT:PSS became an object of intense scientific research, e.g.…”

“…It is thus not astonishing that properties of PEDOT:PSS became an object of intense scientific research, e.g. [1][2][3][4][5][6][7][8] and references therein.…”

“…This enabled us to account for contributions from the PSS part within the Tauc-Lorentz optical model and from the PE-DOT part within the Drude-Lorentz model. Moreover, we relate the optical conductivity of the PEDOT part to the electrical specific conductivity of PEDOT:PSS in the frame of the generalized effective medium theory (GEMT) [2,10].…”

Electronic Transport and Anisotropic Conductivity Behavior on PEDOT:PSS Nanoribbons and Nanostructuring Modification by Atomic Force Microscope Nanoshaving

“…A reduction in the crosssectional area is effected by nanoshaving cuts in a unique behavior compared to the conductivity of PEDOT:PSS, which ranges from 10 -3 -10 3 S/cm [37][38][39]. The conductivity of this nanoribbon (Figures 4 and 7) shows a non-constant value and has a strong dependence on the nanoribbon's cross-sectional area and it is observed a strong anisotropy in the conductivity dependence on the crossectional area.…”

Szerkezeti tényezők hatása a vezető polimerek termoelektromos tulajdonságaira

“…Az ebből az oldatból készített polimer rétegekben a PEDOT-ban gazdag régiókat egy PSS-burok veszi körül (mag-héj szerkezet), limitálva ezzel a rétegek vezetését. [77,78] Későbbi vizsgálatok kimutatták, hogy a PEDOT/PSS rétegek utólagos kezelése valamilyen poláris oldószerrel vagy erős savval jelentős javulást okoz a polimer vezetésében, amit a PSS szelektív kioldódásának tudhatunk be. [79][80][81][82][83] Az így kialakított rétegek vezetése szintén az 1000 S cm -1 -es tartományba esik.…”