The electronic structure of n- and p-doped phenyl-capped 3,4-ethylenedioxythiophene trimer

Abstract

Document VersionPublisher's PDF, also known as Version of Record (includes final page, issue and volume numbers)Please check the document version of this publication:• A submitted manuscript is the author's version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website.• The final author version and the galley proof are versions of the publication after peer review.• The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. The phenyl-capped 3,4-ethylenedioxythiophene ͑EDOT͒ trimer is a well-defined oligomer of the related poly͑3,4-ethylenedioxythiophene͒, the conjugated polymer that forms the basis of the commercialized conducting polymer ''PEDOT-PSS.'' EDOT-based oligomers are themselves potential candidates for applications in molecular electronics, such as organic field effect transistors and organic solar cells. Well controlled chemical doping is of importance in such applications, since it enables tuning of important properties such as the electrical conductivity, the position of the Fermi-level, the optical absorption edge, and the quantum efficiency for photovoltaic devices. The effects of chemical doping, both p-type doping with iodine, and n-type doping with lithium, on the electronic structure of condensed molecular solid films of EDOT trimer have been studied using ultraviolet photoelectron spectroscopy and x-ray photoelectron spectroscopy. The results are discussed in terms of parameters important for device applications.

Insulator to semimetallic transition in conducting polymers

“…Our findings revealing the bumpy structure in the DOS can explain the experimental results showing the nonmonotonic behavior of the DOS in PEDOT and related polymers as revealed in studies using the ultraviolet photoelectron spectroscopy [36], conductivity and the Seebeck coefficient [37], and by cyclic voltammetry [38]. Figure 3(c) shows a comparison of the calculated DOS with commonly utilized Gaussian and exponential models of the DOS in conducting polymers.…”

“…A pronounced feature of the DOS of realistic PEDOT is its nonmonotonous character showing the presence of bumps and shoulders. The bumpy structure in the calculated DOS can explain the experimental results showing the nonmonotonic behavior of the DOS in PEDOT and related polymers as revealed in studies using the ultraviolet photoelectron spectroscopy [35], conductivity and the Seebeck coefficient [36], and by cyclic voltammetry [37]. We find that the calculated DOS in a doped PEDOT is not well described by Gaussian or exponential dependencies (often used in phenomenological models) because of its bump structure and because it is essentially nonzero in the gap.…”

Study of PEDOT:PSS-SnO2 nanocomposite film as an anode for polymer electronics

“…This morphological change suggested a reorientation of the polymer chain due to the presence of SnO 2 in PEDOT:PSS film. The surface −OH radicals of SnO 2 nanoparticles could be considered to act as a plasticizer in thermal annealing process, like the case of -OH of sorbitol or ethylene glycol [2,9]. Their electrostatic interaction of PEDOT:PSS was hindered by SnO 2 nanoparticles.…”

Electrochemical synthesis and in situ spectroelectrochemical characterization of poly(3,4-ethylenedioxythiophene) (PEDOT) in room temperature ionic liquids

“…While the p-doping of PEDOT in organic electrolytes has been extensively studied by a variety of methods [19][20][21][22], much less attention has been paid to its properties upon n-doping [7,[23][24][25]. This is mainly due to the instability of the reduced form of PEDOT in organic electrolytes under atmospheric conditions.…”