Dresden 2017 – wissenschaftliches Programm
CPP 70.7: Vortrag
Freitag, 24. März 2017, 12:15–12:30, ZEU 255
Charge transfer recombination at planar hybrid inorganic/organic interfaces — •Ulrich Hörmann1, Fortunato Piersimoni1, Stefan Zeiske1, Lukas Hoffmann2, Thomas Riedl2, and Dieter Neher1 — 1Universität Potsdam, Potsdam, Germany — 2Bergische Universität Wuppertal, Wuppertal, Germany
The role of the intermolecular energy gap in all-organic donor/acceptor heterojunction (HJ) solar cells is well established. In the case of hybrid inorganic/organic HJs the situation is less clear. Recently, Piersimoni et al. have shown that the energy of the hybrid charge transfer (HCT) emission in electroluminescence experiments correlates with the interface energetics determined by UPS and with the open circuit voltage (Voc) of hybrid solar cells . Here we focus on photovoltaic characterization of planar HJs between ZnO or SnOx acceptor layers and different organic donor materials. Tools well established for all-organic solar cells are carefully transferred to these hybrid systems and their validity is confirmed. Reconstruction of the dark jV-curve from light intensity dependent measurement of Voc and the short circuit current gets rid of the otherwise drastic influence of the series resistance in these devices and allows access to the ideality factor associated with the hybrid interface. Temperature dependent characterization in a carefully chosen operation regime allows the extraction of an effective energy gap, whose origin is – opposed to all-organic HJs – not completely clear, yet. With our combined analysis, we shed light on the nature of HCT states and their role for recombination at metal oxide/organic interfaces.
 Piersimoni et al. / Phys. Chem. Lett. 6, 500 (2015)