Journal
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
Volume 141, Issue 47, Pages 18806-18813Publisher
AMER CHEMICAL SOC
DOI: 10.1021/jacs.9b09367
Keywords
-
Categories
Funding
- KAUST
- BASF
- EC FP7 Project SC2 [610115]
- Engineering and Physical Sciences Research Council (EPSRC) [EP/G037515/1, EP/M005143/1]
- EPSRC [EP/M005141/1]
- University of Warwick
- National Science Foundation, Division of Materials Research [1808401]
- U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-AC02-76SF00515]
- Solar Photochemistry Program of Office of Basic Energy Sciences
- U.S. Department of Energy [DE-AC36-08GO28308]
- EC H2020 [643791]
- EPSRC [EP/M005143/1] Funding Source: UKRI
- Division Of Materials Research
- Direct For Mathematical & Physical Scien [1808401] Funding Source: National Science Foundation
Ask authors/readers for more resources
A fused donor, thienobenzo[b]indacenodithiophene (TBIDT), was designed and synthesized using a novel acid-promoted cascade ring closure strategy, and then copolymerized with a benzothiadiazole (BT) monomer. The backbone of TBIDT is an expansion of the well-known indacenodithiophene (IDT) unit and was expected to enhance the charge carrier mobility by improving backbone planarity and facilitating short contacts between polymer chains. However, the optimized field-effect transistors demonstrated an average saturation hole mobility of 0.9 cm(2) V-1 s(-1), lower than the performance of IDT-BT (similar to 1.5 cm(2) V-1 s(-1)). Mobilities extracted from time-resolved microwave conductivity measurements were consistent with the trend in hole mobilities in organic field-effect transistor devices. Scanning tunneling microscopy measurements and computational modeling illustrated that TBIDT-BT exhibits a less ordered microstructure in comparison to IDT-BT. This reveals that a regular side-chain packing density, independent of conformational isomers, is critical to avoid local free volume due to irregular packing, which can host trapping impurities. DFT calculations indicated that TBIDT-BT, despite containing a larger, planar unit, showed less stabilization of planar backbone geometries in comparison to IDT-BT. This is due to the reduced electrostatic stabilizing interactions between the peripheral thiophene of the fused core and the BT unit, resulting in a reduction of the barrier to rotation around the single bond. These insights provide a greater understanding of the general structure-property relationships required for semiconducting polymer repeat units to ensure optimal backbone planarization, as illustrated with IDT-type units, guiding the design of novel semiconducting polymers with extended fused backbones for high-performance field-effect transistors.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available