TY  - JOUR
A1  - Schwarze, Martin
A1  - Schellhammer, Karl Sebastian
A1  - Ortstein, Katrin
A1  - Benduhn, Johannes
A1  - Gaul, Christopher
A1  - Hinderhofer, Alexander
A1  - Toro, Lorena Perdigon
A1  - Scholz, Reinhard
A1  - Kublitski, Jonas
A1  - Roland, Steffen
A1  - Lau, Matthias
A1  - Poelking, Carl
A1  - Andrienko, Denis
A1  - Cuniberti, Gianaurelio
A1  - Schreiber, Frank
A1  - Neher, Dieter
A1  - Vandewal, Koen
A1  - Ortmann, Frank
A1  - Leo, Karl
T1  - Impact of molecular quadrupole moments on the energy levels at organic heterojunctions
JF  - Nature Communications
N2  - The functionality of organic semiconductor devices crucially depends on molecular energies, namely the ionisation energy and the electron affinity. Ionisation energy and electron affinity values of thin films are, however, sensitive to film morphology and composition, making their prediction challenging. In a combined experimental and simulation study on zinc-phthalocyanine and its fluorinated derivatives, we show that changes in ionisation energy as a function of molecular orientation in neat films or mixing ratio in blends are proportional to the molecular quadrupole component along the p-p-stacking direction. We apply these findings to organic solar cells and demonstrate how the electrostatic interactions can be tuned to optimise the energy of the charge-transfer state at the donor-acceptor interface and the dissociation barrier for free charge carrier generation. The confirmation of the correlation between interfacial energies and quadrupole moments for other materials indicates its relevance for small molecules and polymers.
Y1  - 2019
U6  - https://doi.org/10.1038/s41467-019-10435-2
SN  - 2041-1723
VL  - 10
PB  - Nature Publ. Group
CY  - London
ER  -