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 MoS2/MoSe2 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 Moire patterns, specifically at a twist angle of 21.79(degrees) and 30(degrees). 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 semi-conductors, as well as band-gap modulation caused by interlayer coupling between the monolayers. We also observed that the optical sensitivity of the MoS2/MoSe2 heterostructures is extremely enhanced at a twist angle of 60(degrees) 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.

Automated summary

In this study, the structural, mechanical, electronic, and optical properties of a vertically stacked MoS2/MoSe2 heterostructure were investigated using first-principles-based density functional theory calculations. The relative rotation between the monolayers resulted in the formation of beautiful Moire patterns at twist angles of 21.79 degrees and 30 degrees. The heterostructure exhibited low formation energy and high Young's modulus, indicating its thermodynamic and mechanical stability. Moreover, a phase change from direct to indirect band gap semiconductors and modulation of the band gap due to interlayer coupling were observed. The optical sensitivity of the heterostructure was greatly enhanced at a twist angle of 60 degrees in the visible and infrared regions compared to its monolayers. These twist-assisted electronic and optical properties of the heterostructure provide a novel approach for designing 2D stacked nanostructures for next-generation nano- and optoelectronic devices.