Abstract
The formation of polaron pairs is one of the important photophysical processes that take place after the excitation in semiconducting organic polymers. First-principles Ehrenfest excited-state dynamics is a unique tool to investigate ultrafast photoinduced charge carrier dynamics and related nonequilibrium processes involving correlated electron-nuclear dynamics. In this work the formation of polaron pairs and their dynamical evolution in an oligomer of seven thiophene units is investigated with a combined approach of first-principles exciton-nuclear dynamics and wavelet analysis. The real-time formation of a polaron pair can be observed in the dipole evolution during the excited-state dynamics. The possible driving force of the polaron pair formation is investigated through qualitative correlation between the structural dynamics and the dipole evolution. The time-dependent characteristics and spectroscopic consequences of the polaron pair formation are probed using the wavelet analysis.
| Original language | English |
|---|---|
| Pages (from-to) | 7255-7261 |
| Number of pages | 7 |
| Journal | Journal of Physical Chemistry A |
| Volume | 120 |
| Issue number | 37 |
| DOIs | |
| State | Published - Sep 22 2016 |
| Externally published | Yes |
Funding
The development of the first-principles Ehrenfest dynamics is supported by the US Department of Energy (DE-SC0006863). The educational outreach and international scientific collaboration is supported by the National Science Foundation (CHE-1565520). The University of Washington Student Technology Fund provided computational resources to enable this work.
| Funders | Funder number |
|---|---|
| National Science Foundation | CHE-1565520 |
| U.S. Department of Energy | DE-SC0006863 |
| University of Washington |