Friedrich Jonas

Poly(3,4‐ethylenedioxythiophene) and Its Derivatives: Past, Present, and Future

An overview of one of the most successful conducting polymers, poly(3,4-ethylenedioxythiophene) (PEDT) and its derivatives, is presented, detailing its early development, the synthesis of numerous hybrid and derivative materials, along with a description of the broad array of properties accessible and a description of a set of the more prominent applications in which they can be utilized. Synthetic flexibility and facility is the key to the many new 3,4-ethylenedioxythiophene- (EDT-) based monomers, oligomers, and (co) polymers. These (co) polymers provide highly conducting and especially stable doped states, a range of optical properties with electronic bandgaps varying across the entire visible spectrum, and enhanced redox properties, making them useful for numerous electrochemical devices. Present and future applications for PEDT that are discussed include static charge dissipation films and electrode materials in solid electrolyte capacitors.

Electrochemical and spectroscopic characterization of polyalkylenedioxythiophenes

Abstract The electrosynthesis of polyalkylenedioxythiophenes is described, starting with the anodic oxidation of 3,4-ethylenedioxythiophene ( 1 ) or 3,4-trimethylenedioxythiophene ( 2 ). The resulting polymers are extraordinarily stable during charging and discharging. Owing to a narrow band gap, the first long-wavelength absorption in the doped state appears above 900 nm.

PEDT/PSS for efficient hole-injection in hybrid organic light-emitting diodes

Light-emitting diodes have been prepared by depositing three organic layers successively by spin-coat and evaporation techniques. The first layer of PEDT/PSS smoothens the ITO surface, reduces the probability of electrical shorts and is beneficial for a high overall yield of the operating devices. Above all, this layer promotes hole-injection as an important parameter for higher efficiencies and prolonged operation life. The second layer of spin-coated dendritic phenylamines (TDAPB) with high glass transition temperature modulates the injection of holes into the emitting layer, formed by evaporated Alq. By comparing characteristics and operation lifetime data of devices with and without PEDT/PSS it is shown that the combination of polymeric and monomeric organic layers leads to highly efficient devices, opening new ways to modify device architectures.

Technical applications for conductive polymers

Abstract Whereas organic conductors were, for a long time, simply curiosities found in the laboratory, the first technical applications for them are now beginning to emerge. Films coated with polypyrrole meet the demands made on antistatic packaging materials. Considerably better properties permitting long term use under adverse ambient conditions can be obtained by using 3,4-polyalkylenedioxythiophenes.

Gallium Complexes in Three‐Layer Organic Electroluminescent Devices

Organic light-emitting diodes fabricated by subsequently spin-coating two layers-a hole-transporting followed by a metal chelate emissive layer - onto poly(3,4-ethylene-dioxythiophene)/poly(styrenesulfonate) are presentedfor the first time. The electron-hole recombination occurs in a layer consisting of Ga complexes (see Figure), which exhibit high fluorescence quantum yields, and their emission spectra are blue-shifted relative to that of tris(8-hydroxyquinoline) aluminum. By doping this spin-coated emission layer with fluorescent emitters the emission band can be shifted within the visible spectral range.

29.2: Invited Paper: PEDOT‐Based Layers for TCO‐Substitution and Hole‐Injection

The conducting polymer poly(ethylene-dioxythiophene)/poly(styrenesulfonic acid) [PEDOT:PSS] has matured from an antistatic coating into many more elaborated applications within the past decade. Here we report on our ongoing work towards replacing transparent conducting oxides (TCO) layers by highly conducting PEDOT:PSS and improving hole-injection in small molecule and polymer light emitting diodes.

Electrosynthesis of Poly(3,4-ethylenedioxythiophene) and Its Composite with a Polymer Perfluorinated Sulfo-Cationite from Water–Acetonitrile Solutions

Films of poly(3,4-ethylenedioxythiophene) (PEDT) are synthesized during anodic polarization from a water-acetonitrile mixture containing sulfo-cationite MF-4SK and without it. A comparison of electrochemical and spectroelectrochemical characteristics of the films and an elemental analysis evidence the formation of composite PEDT–MF-4SK. The immobilization of the polymer anion in the PEDT matrix is shown to alter its oxidation mechanism. For a neutral composite film, this mechanism includes the exit of sulfo-cationite cations and the entering of supporting anions.