Revealing Atomistic Ion Migration Pathways of Orientation-Dependent Long-Range Cu+ Ion Migration in β-Cu2Se

• DOI: 10.1021/acs.nanolett.5c00109
• Publication Date: 2025-03-03T14:13:27Z
• Authors: Hanwen Hu; Chen Li; Xinyu Guo; Peijie Ma; Lei Yang; Kun Zheng

Understanding the long-range migration behavior of Cu+ ions is essential for stabilizing β-Cu2Se-based thermoelectrics at intermediate temperatures. A pivotal remaining issue that correlation between and short-range hopping has not yet been established. In this study, we conduct in situ Cs-TEM first-principles calculations to investigate β-Cu2Se. The results show preferentially migrate along ⟨111⟩ directions with lower energy barriers higher precipitation rates compared ⟨001⟩ directions. Such orientation-dependent governed by dynamics ions. Along ⟨111⟩, octahedral sites bridge tetrahedral sites, leading a reduced barrier as low 0.19 eV, which promotes direction. These insights highlight significance understanding lattice regulating ion or ionic materials.