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Updated: Nov 22, 2025
Electrochemical Preparation of Poly3,4-Ethylenedioxythiophene Layers on Gold Microelectrodes for Uric Acid-Sensing Applications
Published on: July 28, 2021
The Simplest Model for Doped Poly(3,4-ethylenedioxythiophene) (PEDOT): Single-crystalline EDOT Dimer Radical Cation
Ryohei Kameyama1, Tomoko Fujino1, Shun Dekura1
1The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8581, Japan.
Abstract:
Although doped poly(3,4-ethylenedioxythiophene) (PEDOT) is extensively used in electronic devices, their molecular-weight distributions and inadequately defined structures have hindered the elucidation of their underlying conduction mechanism. In this study, we introduce the simplest discrete oligomer models: EDOT dimer radical cation salts. Single-crystal structural analyses revealed their one-dimensional (1D) columnar structures, in which the donors were uniformly stacked. Band calculations identified 1D metallic band structures with a strong intracolumnar orbital interaction (band width W≈1 eV), implying the origin of the high conductivity of doped PEDOT. Interestingly, the salts exhibited semiconducting behavior reminiscent of genuine Mott states as a result of electron-electron repulsion (U) dominant over W. This study realized basic models with tunable W and U to understand the conduction mechanism of doped PEDOT through structural modification in oligomers, including the conjugation length.
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