TY - JOUR
T1 - The formation of polymer-dopant aggregates as a possible origin of limited doping efficiency at high dopant concentration
AU - Euvrard, Julie
AU - Revaux, Amélie
AU - Bayle, Pierre Alain
AU - Bardet, Michel
AU - Vuillaume, Dominique
AU - Kahn, Antoine
N1 - Funding Information:
A part of this work was carried out at Princeton University and financially supported by a grant of the National Science Foundation ( DMR-1506097 ). We gratefully acknowledge the group of Prof. Seth Marder for providing the dopants. We thank Xin Lin and Andrew Higgins for help with various sample preparations, Simon Charlot for the MEB images and Nathalie Pelissier for the TEM analysis.
Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2018/2
Y1 - 2018/2
N2 - The polymer Poly[(4,8-bis-(2-ethylhexyloxy)-benzo(1,2-b:4,5-b’)dithiophene)-2,6-diyl-alt-(4-(2-ethylhexanoyl)-thieno [3,4-b]thiophene-)-2-6-diyl)] (PBDTTT-c) p-doped with the molecular dopant tris[1-(trifluoroethanoyl)-2-(trifluoromethyl)ethane-1,2-dithiolene] (Mo(tfd-COCF3)3) exhibits a decline in transport properties at high doping concentrations, which limits the performance attainable through organic semiconductor doping. Scanning Electron Microscopy is used to correlate the evolution of hole conductivity and hopping transport activation energy with the formation of aggregates in the layer. Transmission Electron Microscopy with energy-dispersive X-ray analysis along with liquid-state Nuclear Magnetic Resonance experiments are carried out to determine the composition of the aggregates. This study offers an explanation to the limited efficiency of doping at high dopant concentrations and reinforces the need to increase doping efficiency in order to be able to reduce the dopant concentration and not negatively affect conductivity.
AB - The polymer Poly[(4,8-bis-(2-ethylhexyloxy)-benzo(1,2-b:4,5-b’)dithiophene)-2,6-diyl-alt-(4-(2-ethylhexanoyl)-thieno [3,4-b]thiophene-)-2-6-diyl)] (PBDTTT-c) p-doped with the molecular dopant tris[1-(trifluoroethanoyl)-2-(trifluoromethyl)ethane-1,2-dithiolene] (Mo(tfd-COCF3)3) exhibits a decline in transport properties at high doping concentrations, which limits the performance attainable through organic semiconductor doping. Scanning Electron Microscopy is used to correlate the evolution of hole conductivity and hopping transport activation energy with the formation of aggregates in the layer. Transmission Electron Microscopy with energy-dispersive X-ray analysis along with liquid-state Nuclear Magnetic Resonance experiments are carried out to determine the composition of the aggregates. This study offers an explanation to the limited efficiency of doping at high dopant concentrations and reinforces the need to increase doping efficiency in order to be able to reduce the dopant concentration and not negatively affect conductivity.
KW - Molecular doping
KW - Organic semiconductors
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U2 - 10.1016/j.orgel.2017.11.020
DO - 10.1016/j.orgel.2017.11.020
M3 - Article
AN - SCOPUS:85037166757
SN - 1566-1199
VL - 53
SP - 135
EP - 140
JO - Organic Electronics: physics, materials, applications
JF - Organic Electronics: physics, materials, applications
ER -