TY - JOUR
T1 - Approaching disorder-free transport in high-mobility conjugated polymers
AU - Venkateshvaran, Deepak
AU - Nikolka, Mark
AU - Sadhanala, Aditya
AU - Lemaur, Vincent
AU - Zelazny, Mateusz
AU - Kepa, Michal
AU - Hurhangee, Michael
AU - Kronemeijer, Auke Jisk
AU - Pecunia, Vincenzo
AU - Nasrallah, Iyad
AU - Romanov, Igor
AU - Broch, Katharina
AU - McCulloch, Iain
AU - Emin, David
AU - Olivier, Yoann
AU - Cornil, Jerome
AU - Beljonne, David
AU - Sirringhaus, Henning
N1 - Publisher Copyright:
© 2014 Macmillan Publishers Limited. All rights reserved.
PY - 2014/11/20
Y1 - 2014/11/20
N2 - Conjugated polymers enable the production of flexible semiconductor devices that can be processed from solution at low temperatures. Over the past 25 years, device performance has improved greatly as a wide variety of molecular structures have been studied. However, one major limitation has not been overcome; transport properties in polymer films are still limited by pervasive conformational and energetic disorder. This not only limits the rational design of materials with higher performance, but also prevents the study of physical phenomena associated with an extended I-electron delocalization along the polymer backbone. Here we report a comparative transport study of several high-mobility conjugated polymers by field-effect-modulated Seebeck, transistor and sub-bandgap optical absorption measurements. We show that in several of these polymers, most notably in a recently reported, indacenodithiophene-based donor-acceptor copolymer with a near-amorphous microstructure, the charge transport properties approach intrinsic disorder-free limits at which all molecular sites are thermally accessible. Molecular dynamics simulations identify the origin of this long sought-after regime as a planar, torsion-free backbone conformation that is surprisingly resilient to side-chain disorder. Our results provide molecular-design guidelines for disorder-free conjugated polymers.
AB - Conjugated polymers enable the production of flexible semiconductor devices that can be processed from solution at low temperatures. Over the past 25 years, device performance has improved greatly as a wide variety of molecular structures have been studied. However, one major limitation has not been overcome; transport properties in polymer films are still limited by pervasive conformational and energetic disorder. This not only limits the rational design of materials with higher performance, but also prevents the study of physical phenomena associated with an extended I-electron delocalization along the polymer backbone. Here we report a comparative transport study of several high-mobility conjugated polymers by field-effect-modulated Seebeck, transistor and sub-bandgap optical absorption measurements. We show that in several of these polymers, most notably in a recently reported, indacenodithiophene-based donor-acceptor copolymer with a near-amorphous microstructure, the charge transport properties approach intrinsic disorder-free limits at which all molecular sites are thermally accessible. Molecular dynamics simulations identify the origin of this long sought-after regime as a planar, torsion-free backbone conformation that is surprisingly resilient to side-chain disorder. Our results provide molecular-design guidelines for disorder-free conjugated polymers.
UR - http://www.scopus.com/inward/record.url?scp=84911465675&partnerID=8YFLogxK
U2 - 10.1038/nature13854
DO - 10.1038/nature13854
M3 - Article
C2 - 25383522
AN - SCOPUS:84911465675
SN - 0028-0836
VL - 515
SP - 384
EP - 388
JO - NATURE
JF - NATURE
IS - 7527
ER -