Charge transport physics of a unique class of rigid-rod conjugated polymers with fused-ring conjugated units linked by double carbon-carbon bonds

Abstract

We investigate the charge transport physics of a previously unidentified class of electron-deficient conjugated polymers that do not contain any single bonds linking monomer units along the backbone but only double-bond linkages. Such polymers would be expected to behave as rigid rods, but little is known about their actual chain conformations and electronic structure. Here, we present a detailed study of the structural and charge transport properties of a family of four such polymers. By adopting a copolymer design, we achieve high electron mobilities up to 0.5 cm2 V−1 s−1. Field-induced electron spin resonance measurements of charge dynamics provide evidence for relatively slow hopping over, however, long distances. Our work provides important insights into the factors that limit charge transport in this unique class of polymers and allows us to identify molecular design strategies for achieving even higher levels of performance.

Competing single-chain folding and multi-chain aggregation pathways control solution-phase aggregate morphology of organic semiconducting polymers

“…This finding confirms that the poor solvent conditions used here should be a reasonable representation of the conditions that have been experimentally shown to give extended rod-like aggregates. Furthermore, the Kuhn length in single-chain simulations of our CG model, which varied from 9.2 nm and 10.0 nm as the solvent was changed from poor to "good" (see ESI Table S4 †) is similar to the value of 10.2 nm obtained from fitting of smallangle neutron scattering (SANS) data for P(NDI2OD-T2) in DCB, 89 indicating that the model captures the semiflexibility of this polymer reasonably well.…”

Highly Efficient Mixed Conduction in N‐type Fused Small Molecule Semiconductors

“…Polymers with fused and rigid backbones exhibit unique structure and optoelectronic properties. [35][36][37][38] The double-bonds fused structure has the potential to reduce the torsional disorder along the backbone, hence increasing persistence length and charge transport property. [37] Recently such polymers have shown unique charge transport properties due to their recordhigh electron hopping distance guaranteed by their rigid rodlike backbone, with air-stable ambipolar transport shown for the first time.…”

“…[ 37 ] Recently such polymers have shown unique charge transport properties due to their record‐high electron hopping distance guaranteed by their rigid rod‐like backbone, with air‐stable ambipolar transport shown for the first time. [ 35 ] Also because of the rigid‐rod structure, the solution shearing technique has been used to align the polymer film, showing high optical anisotropy, impressive crystallinity, and high electron mobility up to 0.2 cm 2 V −1 s −1 along the alignment direction. [ 36 ] These design criteria have also been proved in two types of high‐performing n‐type OECT polymer materials.…”

n-Type Organic Electrochemical Transistors with High Transconductance and Stability

“…Long shelf-life in ambient conditions would ensure that device characteristics are maintained from the time of production to the one of use. − Shelf-life is also an important consideration for chronic applications where the device will be at off-state for long hours before operation intermediately. Air instability is mainly attributed to the propensity of radical anions to react with H 2 O or O 2 in air, suppressing electron transport. − Shelf-life stability has been tested for P90 doped with tetra-n-butylammonium fluoride for up to 132 days of storage in PBS; however, there are currently no reports of long-term shelf-life and operational stability of n-type OECTs in airbefore use in contact with the fluid of interest . Consequently, there is still an impending need to develop novel n-type OECT materials that combine the ease of processing, high performance, and operational stability.…”