Etch-Free Patterning of Poly(3,4-ethylenedioxythiophene)–Poly(styrenesulfonate) for Optoelectronics

Abstract

Spatial control of the conductivity of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) is demonstrated through the use of ultraviolet (UV) exposure. With appropriate UV exposure, electrical characterization shows that the in-plane sheet resistance of PEDOT:PSS films is increased by 4 orders of magnitude compared to unexposed regions. Characterization of the films using Raman spectroscopy identifies a significant reduction of the inter-ring stretching modes between PEDOT monomers and a morphological shift from the quinoid to benzoid form of PEDOT. Additional analysis using Fourier transform infrared spectroscopy indicates a reduction in film doping and a decrease in C═C vibrational modes that are associated with PEDOT oligomer length. Height and phase images of these films obtained from atomic force microscopy exhibit a loss of phase segregation in the film between the PEDOT grains and PSS regions. Spectroscopic ellipsometry highlights an increase in both the real and imaginary components of the index upon UV exposure. This broad range of analysis consistently suggests that the increased resistivity can be attributed to a significant reduction in material doping caused by scission-driven decomposition of the conductive PEDOT chains. When flood exposure is combined with the use of an appropriate UV blocking mask, patterning in the conductivity of PEDOT:PSS films can be realized. In contrast to other patterning approaches, no resist development or etching is required for the electrical isolation of certain regions. To demonstrate the efficacy of this process, an organic light emitting diode was fabricated with UV-patterned PEDOT:PSS as a hole transport layer. The regions of unexposed PEDOT:PSS produced electroluminescence, whereas those exposed to UV remained unlit, enabling the realization of pixelated illumination with no removal of material.

Electroconductive PEDOT:PSS-based hydrogel prepared by freezing-thawing method

“…PEDOT:PSS based hydrogels can be utilized as electrodes in biofuel cells [20] and biosensors [21, 22], also in optoelectronics where PEDOT:PSS has established itself as the most efficient electroconductive polymer [23, 24], in optogenetics in view of the good cytocompatibility with the neurons [25], in neuroprosthetics where e.g. authors [18] presented the possibility of controlling the behavior of cells bioelectrochemically on the implantable electrodes.…”

A benzimidazole-based conducting polymer and a PMMA–clay nanocomposite containing biosensor platform for glucose sensing

“…0.24 g (33 wt% to laponite) 2-methacryloyloxy)ethyl trimethylammonium chloride solution (MTMA) in 10 mL water were added drop wise at 60 C. 16 mL of purified MMA and 0.074 g AIBN were added to this solution and the temperature increased to 80 C, and stirred at 700 rpm for overnight. After cooling, the solid polymer drops were filtered, washed with water and then dried in vacuum at 80 C. [24] was synthesized according to a previously published procedure by Stille coupling using 4, [1,4]dioxin-7-yl) stannane and dichlorobis(triphenyl phosphine) palladium (II) (Fig. 1 …”

“…Being conductive, flexible, functional and tunable makes these special kinds of polymers very superior and desirable for many applications. They have been proved to be successfully used in solar cells [1,2], OLEDs [3,4], biomedical applications [5][6][7] and many other fields of hot research interests.…”

“…It was shown that combinational use with thermoplastic or conjugated polymers presents improvement in physical and chemical properties including mechanical properties, solvent resistance and anti-corrosion capacities [21][22][23]. In this study, we describe a combinational use of PMMA-clay nanocomposite (PCN) and a conjugated polymer; poly (4-(2,3-dihydrothieno [3,4-b] [1,4]dioxin-5-yl)-7-(2,3-dihydrothieno [3,4-b] [1,4]dioxin-7-yl)-2-benzyl-1H-benzo[d]imidazole) (poly(BIPE)), for the preparation of a glucose biosensor. Glucose oxidase (GOx) was selected as the model enzyme which was immobilized onto the desired surface in the presence of glutaraldehyde.…”

High-Resolution Electrochemical Transistors Defined by Mold-Guided Drying of PEDOT:PSS Liquid Suspension

“… 15 − 17 The polymer conductance is extremely sensitive to ion doping from the environment by modifying the redox conditions of the PEDOT polymer. 18 − 20 Various techniques have been used to pattern PEDOT:PSS materials, which include mask etching, 11 , 21 , 22 soft lithography, 23 nanoimprinting, 24 pulsed laser ablation, 25 direct UV patterning, 26 selective polymerization, 27 , 28 and electrospinning. 29 Most of the approaches are mainly limited by insufficient spatial resolution.…”