Carrier mobility enhancement in poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) having undergone rapid thermal annealing

Abstract

The conjugated polymer poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) is subjected to non-adiabatic rapid thermal processing and exhibits an increase in conductivity through the film. Electrical measurements on an ITO/PEDOT:PSS/Al diode structure display a current-voltage relationship that correlates to space charge limited conduction with the presence of an exponential trap distribution, which is commonly seen in other organic media. With careful application of this current transport theory to the obtained experimental results, the root cause of the conductivity enhancement can be attributed solely to an increase in the charge mobility of carriers in the PEDOT:PSS film. In comparison to an untreated PEDOT:PSS film, processing at 200 °C for 30 s results in a 35% increase in carrier mobility to 0.0128 cm2 V−1 s−1. Values for other material characteristics of PEDOT:PSS can also be extracted from this electrical analysis, and additionally are found to be unchanged with processing. Hole concentration, effective density of states, and total trap density are found to be 7.4 × 1014 cm−3, 1.5 × 1018 cm−3, and 3.7 × 1017 cm−3, respectively.

Quantitative analyses of enhanced thermoelectric properties of modulation-doped PEDOT:PSS/undoped Si (001) nanoscale heterostructures

“…The influence of modulation doping on the electrical conductivity and Seebeck coefficient was numerically assessed using Poisson's equation, where equilibrium band alignment and band bending around the interface was taken into account. Since the transport parameters 36,40,41 and work function [42][43][44] of PEDOT:PSS are highly dependent on the sample preparation, the work function of a representative PEDOT:PSS sample deposited on SiO2 glass was measured using ultraviolet photoemission spectroscopy (UPS), as shown in Figure 4a. By reading the x-intercept of spectra, the work function was estimated as 5.03 eV.…”

Enhancement of hole mobility in hybrid titanium dioxide/poly(3-hexylthiophene) nanocomposites by employing an oligothiophene dye as an interface modifier

“…Samples were then rinsed in acetonitrile : tert-butanol solution and dried in nitrogen followed by dipping in P3HT polymer (Mn = 24,000; Mw:55,000; RR = 95% purchased from Merck Chemicals Ltd.) solution dissolved in chlorobenzene (2mg/ml), overnight at 120 0 C prior to P3HT spin coating, in order to obtain an active layer thickness of about 1 . Subsequently, these samples were coated with an 40 nm layer of highly-conductive Poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate)(PEDOT:PSS) 29 by spin coating before depositing a Au top contact of 40 nm by thermal evaporation through a shadow mask under high vacuum. Finally, silver paste was applied and annealed to improve the contacts during measurements.…”

Tuning effective hyperfine fields in PEDOT:PSS thin films by doping

“…Experimentally, we prepared a series of ≈50 nm thin films by spin coating aqueous solutions containing PE-DOT:PSS (Clevios P VP AI 4083) that were doped with EG with various weight concentrations between 0% and 0.125%. The films were deposited on EDMR compatible device templates which consisted of lithographically patterned indium tin oxide (ITO) bottom electrodes on glass substrates as described elsewhere [24]. After the EG doped PEDOT:PSS film deposition, the devices were capped with thermally evaporated aluminum thin films as top electrodes.…”