skip to main content

DOE PAGESDOE PAGES

Title: Fast Holes, Slow Electrons, and Medium Control of Polaron Size and Mobility in the DA Polymer F8BT

For this research, the nature of electron and hole polarons on poly(9,9-di-n-hexylfluorenyl-2,7-diyl) (pF) and a copolymer poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4,8-diyl)] (F8BT) has been studied by chemical doping, pulse radiolysis, charge modulation spectroscopy, quantum chemical calculations, and microwave conductivity. While pF exhibits very similar behavior in all respects for the electron and the hole, this paper explores the hypothesis that the donor acceptor (push–pull) nature of F8BT will tend to localize charges. Optical spectra and quantum chemical calculations point to an electron localized on the thiadiazole unit in polar liquids but becoming more delocalized as the solvent polarity decreases. Indeed, in the nonpolar solvent benzene, the electron mobility is only 2.7 times lower than that of the hole, which conversely is shown to be delocalized in all environments and has a similar mobility to polarons on the homopolymer polyfluorene. Lastly, advantageous modifications to the optoelectronic properties of conjugated polymers that come about by using alternating donor acceptor repeat units have thus been shown to not significantly hinder charge transport despite the corrugated energy landscape along the backbone.
Authors:
ORCiD logo [1] ;  [1] ;  [2] ;  [3] ; ORCiD logo [1]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States). Chemistry Department
  2. Kyoto Institute of Technology, Matsugaskaki (Japan). Department of Biomolecular Engineering
  3. University of Cambridge (United Kingdom). Cavendish Laboratory
Publication Date:
Report Number(s):
BNL-114115-2017-JA
Journal ID: ISSN 1932-7447; KC0304030
Grant/Contract Number:
SC0012704; AC02-98CH10886
Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 121; Journal Issue: 29; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1376158

Bird, Matthew J., Bakalis, Jin, Asaoka, Sadayuki, Sirringhaus, Henning, and Miller, John R.. Fast Holes, Slow Electrons, and Medium Control of Polaron Size and Mobility in the DA Polymer F8BT. United States: N. p., Web. doi:10.1021/acs.jpcc.7b04602.
Bird, Matthew J., Bakalis, Jin, Asaoka, Sadayuki, Sirringhaus, Henning, & Miller, John R.. Fast Holes, Slow Electrons, and Medium Control of Polaron Size and Mobility in the DA Polymer F8BT. United States. doi:10.1021/acs.jpcc.7b04602.
Bird, Matthew J., Bakalis, Jin, Asaoka, Sadayuki, Sirringhaus, Henning, and Miller, John R.. 2017. "Fast Holes, Slow Electrons, and Medium Control of Polaron Size and Mobility in the DA Polymer F8BT". United States. doi:10.1021/acs.jpcc.7b04602. https://www.osti.gov/servlets/purl/1376158.
@article{osti_1376158,
title = {Fast Holes, Slow Electrons, and Medium Control of Polaron Size and Mobility in the DA Polymer F8BT},
author = {Bird, Matthew J. and Bakalis, Jin and Asaoka, Sadayuki and Sirringhaus, Henning and Miller, John R.},
abstractNote = {For this research, the nature of electron and hole polarons on poly(9,9-di-n-hexylfluorenyl-2,7-diyl) (pF) and a copolymer poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4,8-diyl)] (F8BT) has been studied by chemical doping, pulse radiolysis, charge modulation spectroscopy, quantum chemical calculations, and microwave conductivity. While pF exhibits very similar behavior in all respects for the electron and the hole, this paper explores the hypothesis that the donor acceptor (push–pull) nature of F8BT will tend to localize charges. Optical spectra and quantum chemical calculations point to an electron localized on the thiadiazole unit in polar liquids but becoming more delocalized as the solvent polarity decreases. Indeed, in the nonpolar solvent benzene, the electron mobility is only 2.7 times lower than that of the hole, which conversely is shown to be delocalized in all environments and has a similar mobility to polarons on the homopolymer polyfluorene. Lastly, advantageous modifications to the optoelectronic properties of conjugated polymers that come about by using alternating donor acceptor repeat units have thus been shown to not significantly hinder charge transport despite the corrugated energy landscape along the backbone.},
doi = {10.1021/acs.jpcc.7b04602},
journal = {Journal of Physical Chemistry. C},
number = 29,
volume = 121,
place = {United States},
year = {2017},
month = {6}
}