Work

Subdiffraction Imaging of Carrier Dynamics in Halide Perovskite Semiconductors: Effects of Passivation, Morphology, and Ion Motion

Year: 2025

Type: article

Abstract: We spatially resolve photocarrier dynamics in halide perovskites using time-resolved electrostatic force microscopy (trEFM) to map surface potential equilibration during photoexcitation. We present a unified interpretation of trEFM, which measures the evolution of the surface potential in response to photoexcitation. We show that trEFM measurements correlate with surface recombination velocity and carrier lifetimes, validated with time-resolved photoluminescence imaging. We further validate the interpretation of trEFM through wavelength- and intensity-dependent measurements and with drift-diffusion simulations. We compare several passivation agents, including (3-aminopropyl)trimethoxysilane (APTMS), [3-(2-aminoethylamino)propyl]trimethoxysilane (AEAPTMS), and phenethylammonium iodide (PEAI). The results reveal heterogeneity in surface potential equilibration times that correlates with perovskite film morphology and nanoscale variations in recombination dynamics following surface passivation. Not only do our results highlight the potential for further improvement of passivation strategies, but also the necessity of high spatial and temporal resolution methods, like trEFM, to evaluate next-generation semiconductors.

Source: ACS Nano

DOI: 10.1021/acsnano.5c05425

Authors: Madeleine D. Breshears, Justin Pothoof, Rajiv Giridharagopal, David S. Ginger

Institution: University of Washington

Language: English

Topic: Perovskite Materials and Applications

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: green