Regensburg 2022 – wissenschaftliches Programm
KFM 20.2: Vortrag
Mittwoch, 7. September 2022, 15:15–15:30, H34
Influence of the Ionic Liquid BMIMBF4 on the film formation and optoelectronic properties of MAPbI3 — •Simon Biberger, Konstantin Schötz, Philipp Ramming, Nico Leupold, Ralf Moos, Anna Köhler, Helen Grüninger, and Fabian Panzer — University of Bayreuth, Bayreuth, Germany
Today, metal halide perovskite solar cells (PSCs) are one of the most promising emerging photovoltaic technologies. However, their still limited stability is a main hurdle for their successful commercialization. In the past, various approaches have been developed to improve the long-term stability and performance of PSCs. Here ionic liquids (IL) as additives have attracted much attention as they passivate defects and suppress ion migration. In this work, we investigate the effect of the IL BMIMBF4 on the film formation and optoelectronic properties of the model halide perovskite MAPbI3. By multimodal in situ optical spectroscopy, we investigate the formation of the perovskite film during solution processing via one-step spin coating and a solvent engineering approach and how the film formation alters when the IL is added to the precursor solution. We find that the IL does not impact the formation of perovskite-solvent complexes, but the perovskite growth rate decreases with increasing IL content in the precursor solution. Additionally, we reveal that the IL already interacts with precursor materials and changes the evolution of the PbI42− properties. Thus, our work provides important insights into how decisive ILs impact the sensitive interconnection between precursor properties, film formation process and final optoelectronic functionality of perovskite thin films.