Dresden 2020 – scientific programme
The DPG Spring Meeting in Dresden had to be cancelled! Read more ...
Parts | Days | Selection | Search | Updates | Downloads | Help
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 53: Perovskite and photovoltaics II (joint session HL/CPP)
CPP 53.5: Talk
Tuesday, March 17, 2020, 15:00–15:15, POT 251
Ion Migration Induced Modification of the Interfacial Energetics in Perovskite Solar Cells and its Effect on Device Performance — •Joshua Kreß1,3,4, Qingzhi An1,3,4, Nir Tessler2, and Yana Vaynzof1,3,4 — 1TU Dresden — 2Technion, Haifa — 3Integrated Center for Applied Physics and Photonics — 4Center for Advancing Electronics Dresden
The migration of ions in perovskite materials has been linked to many negative phenomena such as hysteresis and device degradation. Herein, we demonstrate that, under certain conditions, the migration of ions may also lead to an improvement in device performance. Specifically, by performing ultra-violet photoemission spectroscopy depth profiling experiments, we show that upon the application of an electric field during PV characterization of MAPbI3 inverted architecture solar cells, the migration of iodine ions to the interface between the perovskite active layer and electron extraction layer results in the modification of the electronic structure at that interface. The increase in the density of iodine ions leads to a band bending, resembling the electronic structure of iodine-rich overstoichiometric MAPbI3 films. This change in the interfacial electronic structure results in a significant enhancement of the built-in potential and open-circuit voltage of the photovoltaic cells in subsequent measurements, commonly observed by researchers in the field. Finally, our results are corroborated by numerical device simulations which include the presence and migration of ions.