Transition metal dichalcogenides (TMDs) have emerged as promising 2D materials that can be atomically thin semiconductors, semimetals, metals, or even superconductors. These materials consist of transition metal atoms sandwiched between two layers of chalcogen atoms. Their innate layered structure stems from the existence of strong intralayer bonding forces and weak interlayer van der Waals interactions. [1] Recently, studies have uncovered a Layered MoS 2 is a prospective candidate for use in energy harvesting, valleytronics, and nanoelectronics. Its properties strongly related to its stacking configuration and the number of layers. Due to its atomically thin nature, understanding the atomic-level and structural modifications of 2D transition metal dichalcogenides is still underdeveloped, particularly the spatial control and selective precision. Therefore, the development of nanofabrication techniques is essential. Here, an atomic-scale approach used to sculpt 2D few-layer MoS 2 into lateral heterojunctions via in situ scanning/transmission electron microscopy (STEM/TEM) is developed. The dynamic evolution is tracked using ultrafast and high-resolution filming equipment. The assembly behaviors inherent to few-layer 2D-materials are observed during the process and included the following: scrolling, folding, etching, and restructuring. Atomic resolution STEM is employed to identify the layer variation and stacking sequence for this new 2D-architecture. Subsequent energy-dispersive X-ray spectroscopy and electron energy loss spectroscopy analyses are performed to corroborate the elemental distribution. This sculpting technique that is established allows for the formation of sub-10 nm features, produces diverse nanostructures, and preserves the crystallinity of the material. The lateral heterointerfaces created in this study also pave the way for the design of quantumrelevant geometries, flexible optoelectronics, and energy storage devices.

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