Atomic structural catalogue of defects and vertical stacking in 2H/3R mixed polytype multilayer WS2 pyramids

Journal article

We examine the atomic structure of chemical vapour deposition grown multilayer WS₂ pyramids using aberration corrected annular dark field scanning transmission electron microscopy coupled with an in situ heating holder. The stacking orders and specific types of defects after partial degradation by S and W atomic loss at high temperature are resolved layer-by-layer. Our study of an individual WS₂ pyramid with at least six layers, reveals a mixed 2H and 3R polytype stacking. Etching occurred both top and bottom of the WS₂ pyramid, which aids in determining the exact vertical layer stacking configurations in the thicker regions. We provide an extensive catalogue of the contrast profiles associated with defects in WS₂ as a function of layer number and stacking type, as imaged using ADF-STEM. These results provide extensive details about the identification of a wide range of defects in S₂ layers, and the unique ADF-STEM contrast patterns that arise from complex multilayer stacking.

Authors: Ryu, G; Chen, J; Wen, Y; Zhou, S; Chang, R

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Royal Society of Chemistry
• Journal: Nanoscale
• Volume: 11
• Issue: 22
• Pages: 10859-10871
• Publication date: 2019-05-28
• Acceptance date: 2019-05-17
• DOI: 10.1039/c9nr01783f
• EISSN: 2040-3372
• ISSN: 2040-3364
• Pmid: 31135012
• Language: English