Controlled epitaxial growth of strain-induced large-area bilayer MoS2 by chemical vapor deposition based on two-stage strategy

Two-dimensional (2D) bilayer transition metal dichalcogenides (TMDCs) have attracted considerable attention due to their promising applications in the fields of electronics, optoelectronics , valleytronics and nonlinear optics . However, the precise synthesis of large-area, high-yield and uniform bilayer MoS 2 semiconductors remains a significant challenge. Herein, we have developed one two-stage chemical vapor deposition strategy based on strain engineering, enabling the controlled preparation of large-area (4 × 6 cm 2 ) bilayer MoS 2 nanostructures . Systematic characterizations indicate that compressive strain was introduced during the growth of first layer MoS 2 , which effectively induces the synthesis of the second layer MoS 2 . First-principles calculations based on density functional theory further reveal the mechanism of strain induced controllable growth of bilayer MoS 2 . Field-effect transistors based on AA and AB stacking bilayer MoS 2 have been fabricated exhibiting excellent electronic properties. Our work provides a new pathway for the precise preparation of bilayer TMDCs nanostructures, offering experimental support for their application in the field of electronic and optoelectronic devices .