Spatial variation in nanoscale wear behavior of chemical vapor deposited monolayer WS2

Two-dimensional (2D) materials are potential solid lubricants for a wide range of tribological applications. However, such atomically thin lubricants require detailed understanding of mechanisms underlying their tribological characteristics. In the present study, the nanoscale wear behavior of chemical vapor deposition (CVD) grown monolayer tungsten disulfide (WS2) was investigated using a combination of atomic force mi-croscopy (AFM) and molecular dynamics (MD) simulations. The critical load to initiate wear in the interior region of the WS2 monolayer was found to be higher than the regions near the edge. Experimental findings also reveal significant variability in critical load values in both regions. The observed difference in wear behavior can be attributed to the presence of structural defects as elucidated from MD simulations. Our combined experi-mental and simulation study provides fundamental insights into the atomistic wear mechanism of monolayer WS2.

Automated summary

The nanoscale wear behavior of monolayer WS2 was investigated using a combination of AFM and MD simulations. The critical load to initiate wear was found to be higher in the interior region compared to the edge region, and there was significant variability in critical load values in both regions. MD simulations revealed that structural defects could explain the observed difference in wear behavior.