Twist-engineered tunability in vertical MoS2/MoSe2 heterostructure

Two-dimensional (2D) layered materials and its heterostructures grab a lot of attention because of their outstanding electronic properties for wide area of applications. In this work, the structural, mechanical, electronic and optical properties of a vertically stacked MoS(_2)/MoSe(_2) heterostructure have been studied using first-principles-based density functional theory (DFT) calculations. The relative rotation between the monolayers leads to the formation of beautiful Moiré patterns, specifically at a twist angle of (21.79^circ) and (30^circ). The low formation energy and Young’s modulus reflect the thermodynamic and mechanical stability of this heterostructure, respectively. Furthermore, there is a phase change from direct to indirect band-gap semiconductors, as well as band-gap modulation caused by interlayer coupling between the monolayers. We also observed that the optical sensitivity of the MoS(_2)/MoSe(_2) heterostructures is extremely enhanced at a twist angle of (60^circ) in the visible and infrared regions as compared to its monolayers. The twist-assisted electronic and optical properties of this heterostructure open a novel route to design the 2D stacked nanostructures for next-generation nano- and opto-electronic devices.