Transparent Conducting Polymers

Fabrication of reduced graphene oxide modified poly(3,4-ethylenedioxythiophene) polystyrene sulfonate based transparent conducting electrodes for flexible optoelectronic application

Present article reports on reduced graphene oxide (rGO) modified poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) based transparent conducting electrodes for flexible optoelectronic applications. PEDOT: PSS samples embedded with different rGO concentrations i.e. 0, 1, 2, 3, 4, 5 wt% were prepared and later on, bar coated on polyethylene terephthalate substrate using a 30 μm wire size bar. Various parameters including sheet resistance, bending test (outside and inside bending), optical transmittance etc. were estimated. Our analysis indicates that the samples with 1 wt% rGO possess improved results i.e. low sheet resistance (315 ± 8 Ω/sq.) and high transmittance (~ 74%). Additionally, the sample shows low electrical resistance variation up to 12% (maximum increase) during outward bending and 9% (maximum decrease) during inward bending of the sample for bending curvature from 20 to 100 m−1.

Improvement in Half-Life of Organic Solar Cells by Using a Blended Hole Extraction Layer Consisting of PEDOT:PSS and Conjugated Polymer Electrolyte

In this study, we fabricated conventional structured organic solar cells (OSCs) by introducing a hole extraction layer (HEL) that consisted of poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) and conjugated polymer electrolyte (CPE) poly[9,9-bis(4'-sulfonatobutyl)fluorene-alt-thiophene] (PFT-D). PFT-D has a -SO₃^- functional group that acts as a conjugate base against the -SO₃H of PSS. In addition, the molecular dipole of PFT-D can screen the Coulombic attraction between PEDOT chains and PSS chains. By blending PEDOT:PSS and PFT-D, the acidity of the HEL solution and changes to the surface morphology and potential of the HEL film as a function of exposure time in air were reduced. As a result, the half-life of the OSC fabricated with blended HEL was five times better at room temperature and 40% humidity without encapsulation as compared to the pristine PEDOT:PSS-based device.

PEDOT:PSS Films with Metallic Conductivity through a Treatment with Common Organic Solutions of Organic Salts and Their Application as a Transparent Electrode of Polymer Solar Cells

A transparent electrode is an indispensable component of optoelectronic devices, and there as been a search for substitutes of indium tin oxide (ITO) as the transparent electrode. Poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate) (

PEDOT

PSS) is a conducting polymer that is very promising as the next generation of materials for the transparent electrode if it can obtain conductivity as high as that of ITO. Here, we report the treatment of

PEDOT

PSS with organic solutions to significantly enhance its conductivity. Common organic solvents like dimethylformamide and γ-butyrolactone and common organic salts like methylammonium iodide and methylammonium bromide are used for the organic solutions. The conductivity of pristine

PEDOT

PSS films is only ∼0.2 S/cm, and it can be increased to higher than 2100 S/cm. The conductivity enhancement is much more significant than control treatments of

PEDOT

PSS films with neat organic solvents or aqueous solutions of the organic salts. The mechanism for the conductivity enhancement is the synergetic effects of both the organic salts and organic solvents on the microstructure and composition of

PEDOT

PSS. They induce the segregation of some PSSH chains from

PEDOT

PSS. Highly conductive

PEDOT

PSS films were studied as the transparent electrode of polymer solar cells. The photovoltaic efficiency is comparable to that with an ITO transparent electrode.