Fundamentals of Organic Donor-Acceptor Complexes
Charge-carrier separation at the donor-acceptor interface.
The generation of free charge carriers in organic absorber materials usually requires a donor-acceptor interface at which strongly bound excitons are separated. Such donor-acceptor complexes are important for organic solar cells, organic photodetectors, organic “exciplex” light emitting diodes [S. Ullbrich, J. Benduhn, X. Jia et al. Nature Materials 18 (2019)], as well as molecular doping in organic semiconductors [M. L. Tietze et al. Nature Communication 9 (2018)]. Therefore, understanding the physics of these intermolecular states is essential to improve future devices. Recently, the impact of quadrupole moments [M. Schwarze et al. Nature Communication 10 (2019)] were discovered and the nature of the line-shape broadening could be revealed [K. Tvingstedt et al. Materials Horizon 7 (2020)].