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Title: Role of tilt grain boundaries on the structural integrity of WSe 2 monolayers
Transition metal dichalcogenides (TMDCs) are potential materials for future optoelectronic devices. Grain boundaries (GBs) can significantly influence the optoelectronic properties of TMDC materials. Here, we have investigated the mechanical characteristics of tungsten diselenide (WSe 2 ) monolayers and failure process with symmetric tilt GBs using ReaxFF molecular dynamics simulations. In particular, the effects of topological defects, loading rates, and temperatures are investigated. We considered nine different grain boundary structures of monolayer WSe 2 , of which six are armchair (AC) tilt structures, and the remaining three are zigzag (ZZ) tilt structures. Our results indicate that both tensile strength and fracture strain of WSe 2 with symmetric tilt GBs decrease as the temperature increases. We revealed an interfacial phase transition for high-angle GBs reduces the elastic strain energy within the interface at finite temperatures. Furthermore, brittle cracking is the dominant failure mode in the WSe 2 monolayer with tilted GBs. WSe 2 GB structures showed more strain rate sensitivity at high temperatures than at low temperatures.  more » « less
Award ID(s):
2042683
PAR ID:
10392799
Author(s) / Creator(s):
; ; ; ; ;
Date Published:
Journal Name:
Physical Chemistry Chemical Physics
Volume:
24
Issue:
44
ISSN:
1463-9076
Page Range / eLocation ID:
27241 to 27249
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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