Molybdenum disulfide (MoS2) and bismuth telluride (Bi2Te3) are the two
most common types of structures adopted by 2D chalcogenides. In view
of their unique physical properties and structure, 2D chalcogenides have
potential applications in various fields. However, the excellent properties of
these 2D crystals depend critically on their crystal structures, where defects,
cracks, holes, or even greater damage can be inevitably introduced during
the preparation and transferring processes. Such defects adversely impact
the performance of devices made from 2D chalcogenides and, hence, it is
important to develop ways to intuitively and precisely repair these 2D crystals
on the atomic scale, so as to realize high-reliability devices from these
structures. Here, an in situ study of the repair of the nanopores in MoS2 and
Bi2Te3 is carried out under electron beam irradiation by transmission electron
microscopy. The experimental conditions allow visualization of the structural
dynamics of MoS2 and Bi2Te3 crystals with unprecedented resolution. Realtime
observation of the healing of defects at atomic resolution can potentially
help to reproducibly fabricate and simultaneously image single-crystalline
free-standing 2D chalcogenides. Thus, these findings demonstrate the
viability of using an electron beam as an effective tool to precisely engineer
materials to suit desired applications in the future. |
Publication: Shen Y , Xu T , Tan X , et al. In Situ Repair of 2D Chalcogenides under Electron Beam Irradiation[J]. Advanced Materials, 2018:1705954.
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