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

Abstract

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 MoS2 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 cm2) bilayer MoS2 nanostructures. Systematic characterizations indicate that compressive strain was introduced during the growth of first layer MoS2, which effectively induces the synthesis of the second layer MoS2. First-principles calculations based on density functional theory further reveal the mechanism of strain induced controllable growth of bilayer MoS2. Field-effect transistors based on AA and AB stacking bilayer MoS2 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.