Stress-Guided Anisotropic Etching of MoS2 Nanostructures with Spatial Control over Edge Structure and Morphology
The on-demand patterning of two-dimensional transition metal dichalcogenides (TMDs) with tailored edges is critical for electronic and optoelectronic applications but remains technically challenging. Here, we report a stress-guided anisotropic etching strategy for producing large-area, well-ordered MoS2 nanostructures, including nano-ribbons and nano-squares, without templates. By applying uniaxial cumulative stress followed by selective thermal etching, MoS2 monolayers are statistically etched into ribbon-like structures whose width inversely correlates with applied stress magnitude. The newly etched edges are macroscopically straight or serrated, predominantly Mo-zigzag terminated, and enhance photoluminescence by a factor of ~8.0. The edge type depends on the angle between stress direction and crystallographic orientation, corroborated by theoretical calculations. Biaxial stressing generates well-defined nano-squares, offering a scalable, versatile patterning route for engineering 2D materials with tailored functional edges, promising for electrocatalytic and optoelectronic applications.