2024/12/05 by Madeleine D. Breshears, Justin Pothoof, Breshears, Madeleine D. +5
Engineering · Materials Science · #Perovskite Materials and Applications #Solid-state spectroscopy and crystallography #Luminescence Properties of Advanced Materials
paper · pdf · doi:10.48550/arxiv.2412.04423
We spatially resolve photocarrier dynamics in halide perovskites using time-resolved electrostatic force microscopy (trEFM) to map surface potential equilibration during photoexcitation. Following treatment with different surface passivation agents, we show that trEFM probes dynamics directly related to surface recombination velocity and carrier lifetimes correlated with time-resolved photoluminescence. Our results reveal nanoscale variations in recombination dynamics following surface passivation. We also observe heterogeneity in surface potential equilibration times dependent on perovskite film morphology. We combine wavelength- and intensity-dependent measurements with drift-diffusion simulations to disentangle the influence of carrier recombination and ion migration on surface potential equilibration. These results demonstrate that we can use mechanical detection to image electronic carrier recombination dynamics in perovskites below the optical diffraction limit while also showing the potential for future improvements in heterogeneity of surface passivation.