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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 33: Hybrid and Perovskite Photovoltaics I
CPP 33.5: Talk
Wednesday, March 20, 2024, 17:30–17:45, H 0106
Local Charge Carrier Dynamics in Lead Halide Perovskites by Nano Surface Photovoltage Spectroscopy — Yenal Yalcinkaya1, Pascal Rohrbeck1, Lukas Schmidt-Mende2, and •Stefan A.L. Weber1,3 — 1MPI for Polymer Research, Mainz — 2Department of Physics, University of Konstanz — 3Institute for Photovoltaics, University of Stuttgart
Understanding electron and ion dynamics is an important task for improving lead halide perovskites based solar cells and related devices. Perovskite materials have a delicate nano- and micro structure that influences the device parameters. This study investigates the spatial defect distribution in the vicinity of grain boundaries (GB). To this end, we introduce Nano surface photovoltage spectroscopy (Nano-SPV) via time-resolved Kelvin probe force microscopy (tr-KPFM) [1,2]. By measuring the SPV decay on perovskite samples with small, large, and passivated grains, areas of increased charge carrier recombination, ion migration, and defects were locally detected [3]. Our results clearly show an improved uniformity of SPV and SPV decay distribution within the perovskite films upon passivation. Furthermore, the perovskite films with large grains show better recombination properties based on SPV decay and ideality factor values.
[1] Axt et al. Beilstein J. Nanotechnol. 9, 1809 (2018). [2] Weber et al., Energy Environ. Sci. 11, 2404 (2018). [3] Yalcinkaya et al. Adv. Opt. Mater. 2301318 (2023).
Keywords: Kelvin Probe Force Microscopy; Hybrid Perovskites; Surface Photovoltage Spectroscopy; Nanoscale structure; defects