Ionic Liquid Designed for PEDOT:PSS Conductivity Enhancement.
Poly-3,4-ethylenedioxythiophene:polystyrenesulfonate (PEDOT:PSS) is a water-processable conducting polymer with promise for use in transparent flexible electrodes and thermoelectric devices, but its conductivity is not satisfactory. Its low conductivity is attributed to the formation of hydrophilic/...
| Published in: | Journal of the American Chemical Society Vol. 140; no. 16; pp. 5375 - 5385 |
|---|---|
| Main Authors: | , , , , |
| Format: | Article |
| Published: |
American Chemical Society
4/25/2018
|
| Subjects: | |
| Online Access: | View this record in EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=129345624&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 129345624 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 4/25/2018 vid: 140 iid: 16 pid: 997 pub: American Chemical Society artinfo: ui: 129345624 10.1021/jacs.7b10306 ppf: 5375 ppct: 10 formats: tig: atl: Ionic Liquid Designed for PEDOT:PSS Conductivity Enhancement. aug: au: de Izarra, Ambroise Seongjin Park Jinhee Lee Lansac, Yves Yun Hee Jang affil: Department of Energy Science and Engineering, DGIST, Daegu 42988, Korea GREMAN, UMR 7347, CNRS, Université de Tours, 37200 Tours, France Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, 91405 Orsay, France su: Ionic liquids Electric conductivity Conducting polymers Ion exchange (Chemistry) Electrodes Thermoelectric apparatus & appliances Density functional theory sug: subj: Ionic liquids Electric conductivity Conducting polymers Ion exchange (Chemistry) Electrodes Thermoelectric apparatus & appliances Density functional theory ab: Poly-3,4-ethylenedioxythiophene:polystyrenesulfonate (PEDOT:PSS) is a water-processable conducting polymer with promise for use in transparent flexible electrodes and thermoelectric devices, but its conductivity is not satisfactory. Its low conductivity is attributed to the formation of hydrophilic/insulating PSS outer layers encapsulating the conducting/hydrophobic p-doped PEDOT cores. Recently a significant conductivity enhancement has been achieved by adding ionic liquid (IL). It is believed that ion exchange between PEDOT:PSS and IL components helps PEDOT to decouple from PSS and to grow into large-scale conducting domains, but the exact mechanism is still under debate. Here we show through free energy calculations using density functional theory on a minimal model that the most efficient IL pairs are the least tightly bound ones with the lowest binding energies, which would lead to the most efficient ion exchange with PEDOT:PSS. This spontaneous ion exchange followed by nanophase segregation between PEDOT and PSS, with formation of a π-stacked PEDOT aggregate decorated by IL anions, is also supported by molecular dynamics performed on larger PEDOT:PSS models in solution. We also show that the most efficient IL anions would sustain the highest amount of charge carriers uniformly distributed along the PEDOT backbone to further enhance the conductivity, providing that they remain in the PEDOT domain after the ion exchange. Hence, our design principle is that the high-performance IL should induce not only an efficient ion exchange with PEDOT:PSS to improve the PEDOT morphology (to increase mobility) but also a uniform high-level p-doping of PEDOT (to enhance intrinsic conductivity). Based on this principle, a promising (electron-withdrawing, but bulky, soft, and hydrophobic) new IL pair is proposed. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2018 holdings: @attributes: islocal: N |
|---|