Mapping Surface Defects and Ion Migration in Mixed-Cation Perovskite Crystals
Published:
R. O. Nughays, K. Almasabi, S. Nematulloev, L. Wang, T. Bian, I. Nadinov, B. Irziqat, G. T. Harrison, S. Fatayer, J. Yin, O. M. Bakr, O. F. Mohammed, Advanced Science (2024).
This work directly visualizes surface defects and ion migration pathways in mixed-cation perovskite single crystals using 4D ultrafast electron microscopy. By resolving charge-carrier dynamics in real space and time, we demonstrate how localized defect environments and ionic motion modulate surface transport and recombination. The results clarify the nanoscale origins of instability and performance variability in perovskite optoelectronic devices.