Tuning the degree of oxidation and electron delocalization of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) with solid-electrolyte

Date
2017-10
Advisor
Instructor
Source Title
Applied Surface Science
Print ISSN
0169-4332
Electronic ISSN
Publisher
Elsevier
Volume
419
Issue
Pages
770 - 777
Language
English
Type
Article
Journal Title
Journal ISSN
Volume Title
Abstract

We report on the effects of ionic interaction on the electronic structure of PEDOT:PSS where the oxidation state of PEDOT is an import aspect for various applications. Additional ionic interactions are introduced and controlled by varying the fraction of poly(ethylene oxide) (PEO). These interactions are balanced against the inherent cohesive forces within each of the polymers constituting intertwined networks. Raman spectra evidenced a peak-shift as high as ∼14 cm−1 for C[dbnd]C vibrational region which suggested increasing degree of oxidation of PEDOT for higher PEO fractions. Changes to the single and bipolaronic absorption bands support the results from the Raman spectra. For highest PEO fraction neutral-PEDOT and lowered bipolaron density is attributed to localization of PEDOT chains within PEO matrix. Interestingly, for higher PEO fractions the electronic density of states (DOS) of HOMO and core-levels (S2p, C1s and O1s) suggested increased degree of oxidation and electron localization on PEDOT. Near and below (∼12 eV) Fermi level, contribution to the O2p and C2p atomic orbitals depicted significantly different DOS. Also we note energetic shift for O2s/C2s and bonding σCC atomic and molecular DOS, respectively. The correlation between some surface and bulk-related properties suggests the uniformity of the blend material which might be vital for the application in electrochemical devices.

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Keywords
HOMO structure, Ionic interaction and intertwined polymer network, XPS, Conducting polymers, Electrolytes, Electronic density of states, Electronic structure, Ethylene, Oxidation, Polyethylene oxides, Polymers, Quantum chemistry, Raman scattering, X ray photoelectron spectroscopy, Degree of oxidations, Electrochemical devices, Electron delocalization, Electron localizations, Electronic density, Poly (ethylene oxide) (PEO), Poly(3 ,4-ethylenedioxythiophene):poly(styrenesulfonate), Polymer networks, Solid electrolytes
Citation
Published Version (Please cite this version)