Structure and Properties of Dual-doped PEDOT:PSS Multilayer Films

Abstract

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is the most successful transparent conductive polymer widely used in functional organic devices. However, its potential in fabrication of highly conductive electrodes still has not been fully explored. This paper is an attempt to fill the existing gap of knowledge on possible post-treatments of dimethyl sulfoxide (DMSO)-doped PEDOT:PSS thin films. In the present study, surface morphology, optical and electrical properties of untreated and sulfuric acid treated DMSO-doped PEDOT:PSS multilayers on the glass coverslip substrates are examined. It is demonstrated that short-time sulfuric acid treatment enhances electrical and optical properties, and smoothens surface of the transparent conductive films. Enhancement of electrical conductivity by more than 30 % can be associated with increase in doping level, removal of excess PSS and accompanied shape alterations of the conjugated PEDOT chains. Acid treatment also results in smoother transmittance spectra and a slight improvement of optical transparency. Hence, sulfuric acid post-treatment can be considered as a simple and inexpensive technique for the complementary doping of DMSO-doped PEDOT:PSS films with the aim to develop the more effective transparent electrodes.

Concurrent Enhancement of Conductivity and Stability in Water of Poly(3,4‐Ethylenedioxythiophene):Poly(Styrenesulfonate) Films Using an Oxetane Additive

“…The origin of the improved conductivity of the films from HMO:PEDOT:PSS mixtures was investigated on the basis that enhancements on PEDOT:PSS films’ conductivity upon using additives have been generally attributed to more extended PEDOT conducting networks that can be favored by conformational changes of PEDOT chains. [ 28,45–47 ] Hence, we used Raman spectroscopy to investigate the films with improved conductivity because this has been the main technique to assess the conformational characteristics of PEDOT in conducting films. [ 28,31,35,42,45–49 ] Figure 4 collects the Raman spectra, in the region of PEDOT modes, of films exhibiting the highest conductivities, in comparison with films from pristine dispersions (each spectrum was normalized to its maximum intensity).…”

“…[ 28,45–47 ] Hence, we used Raman spectroscopy to investigate the films with improved conductivity because this has been the main technique to assess the conformational characteristics of PEDOT in conducting films. [ 28,31,35,42,45–49 ] Figure 4 collects the Raman spectra, in the region of PEDOT modes, of films exhibiting the highest conductivities, in comparison with films from pristine dispersions (each spectrum was normalized to its maximum intensity). Pristine films from PVP AI 4083 / PH1000 exhibit the main peaks at 1266/1254 cm −1 (Cα–Cα´ inter‐ring stretching), 1369/1367 cm −1 (Cβ−Cβ stretching), 1440/1434 cm −1 (Cα = Cβ symmetric stretching), 1508/1503 cm −1 (Cα = Cβ asymmetric stretching) 1538/1541 cm −1 (splitting of Cα = Cβ asymmetrical stretching), and 1574/1571 cm −1 assigned to the Cα = Cβ asymmetrical stretching vibration modes and CC stretching modes from rings in PSS [ 28,48,49 ] Considering the films prepared from PVP AI 4083, the main band, centered at 1440 cm −1 suffers a small red‐shift, to 1438 cm −1 , and gets narrower, whereas the relative intensity of the other peaks are decreased when the dispersion contains HMO.…”

Potential Applications of Conducting Polymers to Reduce Secondary Bacterial Infections among COVID-19 Patients: a Review

“…Chen et al [ 52 ] reported that DMSO aligned the PEDOT grains which improved the electrical flow between PEDOT grains and increased the conductivity of up to 1100 S/cm. Lucius et al [ 53 ] reported that the cohesion between PEDOT molecules could be one of the factors that improves the electrical conductivity of PEDOT: PSS. The addition of DMSO may breaking the bonds between the inter part of PSS and the cohesion of PEDOT grains.…”

Free-Standing Composite Films Based on Thiol-Ene and PEDOT: PSS Layers for Optoelectronic Applications

“…The water dispersions of PEDOT:PSS colloids were synthesized by oxidative polymerization of EDOT in the presence of the PSS. Details of the synthesis procedure have been reported previously [ 7 ]. The PEDOT:PSS dispersions containing DMSO (50 μL/mL) were spin-coated on the one side of the free-standing PETMP-TTT at 2000 rpm for 30 s. Afterwards, it was dried at room temperature for 24 h (this timing ensures slow evaporation of water molecules, which results in more homogeneous and less defective film) and cured on a hot plate at 125 °C for 2 min.…”