Two-dimensional square transition metal dichalcogenides with lateral heterostructures

Fabrication of lateral heterostructures (LHS) is promising for a wide range of next-generation devices and could sufficiently unlock the potential of two-dimensional materials. Herein, we demonstrate the design of lateral heterostructures based on new building materials, namely 1S-MX2 LHS, using first-principles calculations. 1S-MX2 LHS exhibits excellent stability, demonstrating high feasibility in the experiment. The desired bandgap opening can endure application at room temperature and was confirmed in 1S-MX2 LHS with spin-orbit coupling (SOC). A strain strategy further resulted in efficient bandgap engineering and an intriguing phase transition. We also found that black phosphorus can serve as a competent substrate to support 1S-MX2 LHS with a coveted type-II band alignment, allowing versatile functionalized bidirectional heterostructures with built-in device functions. Furthermore, the robust electronic features could be maintained in the 1S-MX2 LHS with larger components. Our findings will not only renew interest in LHS studies by enriching their categories and properties, but also highlight the promise of these lateral heterostructures as appealing materials for future integrated devices.