Organic solar cells containing non-fullerene acceptors such as m-ITIC blended with conjugated polymers have impressive efficiencies. One reason is the low driving force for charge transfer, allowing high photovoltage. However, this might slow down charge generation, leading to a tradeoff between voltage and current.
In contrast, we have recently shown by time-resolved spectroscopy, that both the electron and hole transfer at the donor:acceptor interface remain ultrafast (< 1 ps) even if the driving force approaches zero..

This work was carried out in the group of Prof. Natalie Banerji.

Reference:

• Y. Zhong, M. Causa', G. J. Moore, P. Krauspe, B. Xiao, F. Günther, J. Kublitski, R. Shivhare, J. Benduhn, E. BarOr, S. Mukherjee, K. M. Yallum, J. Réhault, S. C. B. Mannsfeld, D. Neher, L. J. Richter, D. M. DeLongchamp, F. Ortmann, K. Vandewal, E. Zhou, N. Banerji;
  "Sub-picosecond charge-transfer at near-zero driving force in polymer:non-fullerene acceptor blends and bilayers"
  Nature Communications, 2020, 11, 833; doi:10.1038/s41467-020-14549-w