DPG 2021 Spring Meeting will take place virtually on 22-24 March 2021. Park Systems is proud to present its poster in the CPP Poster Session I on 23 March from 4:30 to 6:30 p.m.
Join our Principal Scientist – Ilka Hermes for a poster presentation on “Imaging ferroelastic domains in MAPbI3 perovskite via dual frequency resonance tracking PFM”. Please see the abstract below.
Link: https://bpcppdysoe21.dpg-tagungen.de/
ABSTRACT
Imaging ferroelastic domains in MAPbI3 perovskite via dual frequency resonance tracking PFM
Ilka Hermes1 and Romain Stomp2 — 1Park Systems Europe, Mannheim, Germany —2Zuerich Instruments, Zuerich, Switzerland
Methylammonium lead iodide (MAPbI3)-based photovoltaics have seen an astonishing increase in efficiency due to their unique optoelectronic properties and charge carrier dynamics. Since MAPbI3 crystallizes in a tetragonal perovskite structure, researchers have long suggested that the material features ferroelectricity and -elasticity. These ferroic properties are thought to influence the charge carrier dynamics in MAPbI3 photovoltaics and, therefore, require accurate characterization on the nanoscale, available via piezoresponse force microscopy (PFM). On thin films, a weak piezoresponse often has to be enhanced by driving the electrical excitation of PFM close to the contact resonance of the cantilever. However, the contact resonance depends on a consistent tip-sample contact. Therefore, a high surface roughness or nanomechanical heterogeneities can introduce crosstalk, which exacerbates the data interpretation of the electromechanical sample response. Dual frequency resonance tracking (DFRT) improves the stability of the resonance enhancement via an additional frequency feedback that compensates for shifts in the contact resonance. Here, we demonstrate that DFRT-PFM, available by combining Park Systems atomic force microscopes with Zurich Instruments lock-in amplifiers, not only reduces crosstalk, but also resolves the mechanical contrast on ferroelastic MAPbI3 domains.
