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Healing of Planar Defects in 2D Materials via Grain Boundary Sliding
Author(s) -
Zhao Xiaoxu,
Ji Yujin,
Chen Jianyi,
Fu Wei,
Dan Jiadong,
Liu Yuanyue,
Pennycook Stephen J.,
Zhou Wu,
Loh Kian Ping
Publication year - 2019
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201900237
Subject(s) - materials science , grain boundary , stacking , metastability , atomic units , density functional theory , condensed matter physics , planar , transmission electron microscopy , annealing (glass) , chemical physics , scanning transmission electron microscopy , stacking fault , nanotechnology , crystallography , optoelectronics , composite material , computational chemistry , microstructure , physics , chemistry , computer graphics (images) , nuclear magnetic resonance , quantum mechanics , computer science , dislocation
Understanding the mechanisms and kinetics of defect annihilations, particularly at the atomic scale, is important for the preparation of high‐quality crystals for realizing the full potential of 2D transition metal dichalcogenides (TMDCs) in electronics and quantum photonics. Herein, by performing in situ annealing experiments in an atomic resolution scanning transmission electron microscope, it is found that stacking faults and rotational disorders in multilayered 2D crystals can be healed by grain boundary (GB) sliding, which works like a “wiper blade” to correct all metastable phases into thermodynamically stable phases along its trace. The driving force for GB sliding is the gain in interlayer binding energy as the more stable phase grows at the expanse of the metastable ones. Density functional theory calculations show that the correction of 2D stacking faults is triggered by the ejection of Mo atoms in mirror twin boundaries, followed by the collective migrations of 1D GB. The study highlights the role of the often‐neglected interlayer interactions for defect repair in 2D materials and shows that exploiting these interactions has significant potential for obtaining large‐scale defect‐free 2D films.