Abstract-Electron and Hole Contributions to the Terahertz Photoconductivity of a Conjugated Polymer:Fullerene Blend Identified

 

http://pubs.acs.org/doi/abs/10.1021/jz301013u

 

Carlito S. Ponseca , Hynek Němec,  Nenad Vukmirovic , Sandra Fusco , Ergang Wang , Mats R. Andersson , Pavel Chabera , Arkady Petrovich Yartsev , and Villy Sundstrom

J. Phys. Chem. Lett., Just Accepted Manuscript

DOI: 10.1021/jz301013u

Publication Date (Web): August 17, 2012

Copyright © 2012 American Chemical Society

Time-resolved terahertz spectroscopy was employed for the investigation of charge transport dynamics in benzothiadiazolo-dithiophene polyfluorene ([2,7-(9,9-dioctyl-fluorene)-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3-benzothiadiazole)]) (APFO-3) polymers with various chain lengths and in its monomer form, all blended with an electron acceptor ([6,6]-phenyl-C61-butyric acid methyl ester, PCBM). Upon photoexcitation, charged polaron pairs are created, negative charges are transferred to fullerenes while positive polarons remain on polymers/monomers. Vastly different hole mobility in polymer and monomer blends allows us to distinguish the hole and electron contributions to the carrier mobility.