Understanding the Stability of MAPbBr3 versus MAPbI3: Suppression of Methylammonium Migration and Reduction of Halide Migration
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Updated: Dec 12, 2025

Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films
Published on: September 8, 2017
Lucie McGovern1, Moritz H Futscher1, Loreta A Muscarella1
1Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
Abstract:
Solar cells based on metal halide perovskites often show excellent efficiency but poor stability. This degradation of perovskite devices has been associated with the migration of mobile ions. MAPbBr3 perovskite materials are significantly more stable under ambient conditions than MAPbI3 perovskite materials. In this work, we use transient ion drift to quantify the key characteristics of ion migration in MAPbBr3 perovskite solar cells. We then proceed to compare them with those of MAPbI3 perovskite solar cells. We find that in MAPbBr3, bromide migration is the main process at play and that contrary to the case of MAPbI3, there is no evidence for methylammonium migration. Quantitatively, we find a reduced activation energy, a reduced diffusion coefficient, and a reduced concentration for halide ions in MAPbBr3 compared to MAPbI3. Understanding this difference in mobile ion migration is a crucial step in understanding the enhanced stability of MAPbBr3 versus MAPbI3.
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