Superresolution mapping of energy landscape for single charge carriers in plastic semiconductors.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30333490.
- Also identified by DOI 10.1038/s41467-018-06846-2 and PMC identifier 6193038.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The performance of conjugated polymer devices is largely dictated by charge transport processes. However, it is difficult to obtain a clear relationship between conjugated polymer structures and charge transport properties, due to the complexity of the structure and the dispersive nature of charge transport in conjugated polymers. Here, we develop a method to map the energy landscape for charge transport in conjugated polymers based on simultaneous, correlated charge carrier tracking and single-particle fluorescence spectroscopy. In nanoparticles of the conjugated polymer poly[9,9-dioctylfluorenyl-2,7-diyl)-co-1,4-benzo-{2,1'-3}-thiadiazole)], two dominant chain conformations were observed, a blue-emitting phase (λ<sub>max</sub> = 550 nm) and a red-emitting phase (λ<sub>max</sub> = 595 nm). Hole polarons were trapped within the red phase, only occasionally escaping into the blue phase. Polaron hopping between the red-emitting traps was observed, with transition time ranging from tens of milliseconds to several seconds. These results provide unprecedented nanoscale detail about charge transport at the single carrier level.