Regensburg 2019 – wissenschaftliches Programm
CPP 14.7: Vortrag
Montag, 1. April 2019, 16:45–17:00, H31
Non-fullerene acceptors with tailored properties for organic solar cells — •Anastasia Markina1, Frederic Laquai2, and Denis Andrienko1,2 — 1Max Planck Institute for Polymer Research, Mainz 55128, Germany — 2King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal 23955-6900, Kingdom of Saudi Arabia
One promising method to achieve higher solar cell efficiencies is to replace fullerenes with strongly-absorbing dye molecules, namely, nonfullerene acceptors (NFAs). However, the systematic design of acceptor molecules with tailored properties has yet to be demonstrated. The main difficulty here is that, while fullerenes are electrostatically inert, new acceptor molecules typically have strong static quadrupole moments.
By exploring the long-range electrostatic interaction at the interface, we demonstrate that, for a set of recently developed NFAs, the electrostatic bias potential can be directly related to the stabilization (or destabilization) of charge-transfer (CT) states as well as changes of the photovoltaic gap.
We find that the correlation between quadrupole moments, charge separation efficiency, and CT-state energy predicted by our model, is experimentally reproduced for several different donor /acceptor combinations. This allows us to predict new NFA structures using combinations of readily available molecular building blocks that can potentially reach even higher performances than those currently achieved in state-of-the-art NFA devices.