Theoretical prediction of the electronic structure, optical properties and contact characteristics of a type-I MoS2/MoGe2N4 heterostructure towards optoelectronic devices

Abstract

Recently, the combination of two different two-dimensional (2D) semiconductors to generate van der Waals (vdW) heterostructures has emerged as an effective strategy to tailor their physical properties, paving the way for the development of next-generation devices with improved performance and functionality. In this work, we designed an MoS₂/MoGe₂N₄ heterostructure and explored its electronic structures, optical properties and contact characteristics using first-principles calculations. The MoS₂/MoGe₂N₄ heterostructure is predicted to be energetically, thermally and dynamically stable, indicating its feasibility for experimental synthesis in the future. The MoS₂/MoGe₂N₄ heterostructure forms type-I band alignment, suggesting that it can be considered as a promising material for optoelectronic devices, such as light-emitting diodes, and in laser applications. Furthermore, the type-I MoS₂/MoGe₂N₄ heterostructure has enhanced optical absorption in both the visible and ultraviolet regions. More interestingly, the electronic properties and contact characteristics of the MoS₂/MoGe₂N₄ heterostructure can be tailored by applying in-plane biaxial strain. Under the application of compressive and tensile strains, transformations between type-I and type-II band alignments and between semiconductor and metal can be achieved in the MoS₂/MoGe₂N₄ heterostructure. Our findings could provide useful guidance for experimental synthesis of materials based on the MoS₂/MoGe₂N₄ heterostructure for electronic and optoelectronic applications.