Abstract
The chain conformation of donor-acceptor conjugated polymers (D-A CPs) is critical to their optical and electronic properties. However, probing the conformation of D-A CPs (e.g., persistence length and contour length) at a single-chain level is challenging due to the formation of aggregates in dilute solution, even in a good solvent. In this work, we studied the chain conformation and corresponding optical spectra for high-performance D-A CPs in the single-chain state by multimodal variable-temperature scattering and spectroscopy techniques, as well as by molecular dynamics simulations. We found a critical role of the side-chain length and branch point in the persistence length and optical absorption due to steric effects. Hence, it is important to consider both the chain rigidity and coplanarity of the polymer backbone to achieve desirable optoelectronic properties. Our findings bridge the fundamental knowledge gaps to design new CPs with desired optoelectronic properties via molecular engineering for next-generation electronic devices.
| Original language | English |
|---|---|
| Pages (from-to) | 12928-12940 |
| Number of pages | 13 |
| Journal | Journal of Materials Chemistry A |
| Volume | 11 |
| Issue number | 24 |
| DOIs | |
| State | Published - Feb 14 2023 |
Funding
This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Science under the award numbers of DE-SC0019361 and DE-SC0022050. S. R.-G. thanks the NSERC for financial support through a Discovery under award number RGPIN-2022-04428. Z. L., S. A. T., A. A. and W. X. acknowledge support from the U.S. National Science Foundation under NSF OIA Award No. 2119691 and the College of Engineering at North Dakota State University. T. L. thanks for the support of the National Key Research and Development Project (2022YFE0130600). This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. Part of the research was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility.