Edge‐Termination‐Defined Heteroepitaxy of 2D Lateral Heterostructures Array with Tailored Heterointerfaces

Abstract Heterointerface engineering of 2D transition metal dichalcogenides (2D‐TMDs) based lateral heterostructures provides a pathway for exploring unique heterointerface‐specific properties and achieving tailoring novel functionalities. While various lateral heterostructures are synthesized, synthesis design of high‐quality lateral heterostructures with programmable heterointerfaces remains a challenge. Here, an edge‐termination‐guided epitaxy methodology is reported to synthesize WS 2 ‐WSe 2 lateral heterostructures array with designable heterointerfaces. Anisotropically etched WS 2 ribbons array with alternating zigzag W/S (ZZ‐W/S) terminated edges serve as templates for WSe 2 epitaxial growth, steering distinct heterointerface configurations. Raman‐photoluminescence microscopy confirms the robust formation of structural universality exemplified by WS 2 ‐MoS 2 and WSe 2 ‐MoS 2 systems with tailored interfaces, indicating that such interface‐controlled growth is a generalizable approach for designing 2D heterostructure libraries. STEM characterization reveals edge termination‐dependent structural evolution: ZZ‐W‐terminated heterointerfaces exhibit localized atomic distortion domains, while ZZ‐S‐terminated heterointerfaces maintain coherent lattice continuity, enabling seamless structural transitions at the WS 2 /WSe 2 boundary. These structural differences manifest in distinct optoelectronic properties, with ZZ‐W‐terminated heterointerfaces generating significantly stronger second‐harmonic generation (SHG) response, displaying 40% greater than ZZ‐S‐terminated heterointerfaces. The template‐directed epitaxial growth method provides superior control over heterointerface properties compared to conventional approaches, providing a versatile heterostructure platform for exploring exotic physics and promises a scalable pathway to high performance devices.