Mechanical behavior of single layer MoS2 sheets with aligned defects under uniaxial tension

Compared with a single defect or randomly distributed defects, aligned defects are widely found or artificially designed in structures to realize various functions. However, the mechanical behavior of transition metal dichalcogenides with aligned defects is still unclear, which restricts the blooming application in novel flexible nanodevices. Herein, we report the strength and fracture properties of single layer MoS2 (SLMoS2) sheets with aligned defects under uniaxial tension by numerical calculation and theoretical modeling. It is found that the increase of the number of defects and adjacent spacing leads to the decrease of critical strain as well as tensile strength of both pristine and kirigami MoS2 sheets. Three types of crack propagation phenomena are discovered, and an effective theoretical model is employed to uncover the underlying mechanism of crack deflection phenomenon in SLMoS2 sheets with aligned defects. These results provide important insights into mechanical behavior of SLMoS2 sheets and should be helpful for potential applications of the new two-dimensional material.