Experimental Evidence Relating Charge-Transfer-State Kinetics and Strongly Reduced Bimolecular Recombination in Organic Solar Cells
Nasim Zarrabi, Oskar J Sandberg, Christina Kaiser, Jegadesan Subbiah, David J Jones, Paul Meredith, Ardalan Armin
The Journal of Physical Chemistry Letters | AMER CHEMICAL SOC | Published : 2020
Significantly reduced bimolecular recombination relative to the Langevin recombination rate has been observed in a limited number of donor-acceptor organic semiconductor blends. The strongly reduced recombination has been previously attributed to a high probability for the interfacial charge-transfer (CT) states (formed upon charge encounter) to dissociate back to free charges. However, whether the reduced recombination is due to a suppressed CT-state decay rate or an improved dissociation rate has remained a matter of conjecture. Here we investigate a donor-acceptor material system that exhibits significantly reduced recombination upon solvent annealing. On the basis of detailed balance ana..View full abstract
This work was supported by the Ser Cymru Program through the Welsh Government, the European Regional Development Fund, the Welsh European Funding Office, and the Swansea University strategic initiative in Sustainable Advanced Materials. A.A. is a Ser Cymru II Rising Star Fellow, and P.M. is a Ser Cymru II National Research Chair. N.Z. was supported by a studentship through the Ser Cymru Program II, and C.K. is the recipient of a UKRI EPSRC Doctoral Training Account studentship.