Stacking, Twisting, and Doping Graphene/Molybdenene Bilayers

Stacking two-dimensional materials can enrich the properties of their single-layered counterparts, and these properties can be further enriched by simply twisting the stacking layers with respect to each other. In order to assess this enrichment, we discuss a novel bilayer material made of graphene and molybdenene, that is, a semimetallic and a metallic structure, stacked together in a bilayer material. Using quantum-mechanical calculations based on density functional theory, we examine the structural characteristics and electronic properties of this material in its pristine stacked and also twisted states. We focus on the assessment of the respective modifications in the electronic behavior with respect to the nontwisted bilayer. The trends of twisting the bilayer are further analyzed using unsupervised learning and points to specific correlations in the twisting angles. In order to point to additional pathways to tune the bilayer properties, we investigate the effect of selected doping in both the graphene and molybdenene layers of the bilayer. The respective effects observed are discussed in view of a selective design of ultrathin materials for nanoelectronic applications.