Strain Imaging of Laterally-Stitched Monolayers by Nonlinear Optical Microscopy*

Strain configuration is significant to crystal structure and performance of monolayer two-dimensional lattice. Heterojunction of various monolayer transition metal dichalcogenides (TMD) is emergent route to induce unique symmetry and strain configurations. Here, we realize the synthesis of diverse in-plane artificial lattice by lateral stitching of different monolayer TMD using sequential CVD growth. Highly oriented strain patterns are observed and studied by second harmonic generation imaging of the TMD multijunctions. Strain pattern with lateral and vertical heterostructures are studied using angle resolved second harmonic generation, which is practical to corelate unique properties by direct probing symmetry and strain cofiguration of monolayer TMDs.