Ripples near edge terminals in MoS2 few layers and pyramid nanostructures

Atomically thin transition-metal dichalcogenides are of great interest due to their intriguing physical properties and potential applications. Here, we report our findings from scanning tunneling microscopy and spectroscopy investigations on molybdenum disulfide (MoS2) mono- to few-layers and pyramid nanostructures synthesized through chemical vapor deposition. On the few-layered MoS2 nanoplatelets grown on gallium nitride (GaN) and pyramid nanostructures on highly oriented pyrolytic graphite, we observed an intriguing curved region near the edge terminals. The measured band gap on these curved regions is 1.96 ± 0.10 eV, consistent with the value of the direct band gap in MoS2 monolayers. The curved features near the edge terminals and the associated electronic properties may contribute to the catalytic behaviors of MoS2 nanostructures and have potential applications in future electronic devices and energy-related products based on MoS2 nanostructures.