First-principles study of the electronic and optical properties of layered SnS2/ graphene heterostructure

Owing to its potential for energy harvesting and storage, layered SnS₂ has become increasingly popular in the energy storage and conversion community. The current study proposes a layered stacking configuration of SnS₂/ graphene heterostructure, which could improve its stability and electronic transport properties for optoelectronic and solar cell applications. The study utilizes the first-principles Density Functional Theory approach to investigate the electronic and optical properties of bilayer and sandwich-layered SnS₂/graphene heterostructures for energy storage applications. The low magnitude of the cohesive energy of SnS₂ in both the bi- and sandwich cases ($0.3604\to 0.0057\to 0.0522eV$) of both heterostructures reflect feasible experimental reproducibility. Additionally, a reduction of the band gap $(2.338\to 0.604\to 0.595$ eV) with corresponding charge redistribution is observed, suggesting increased electron conductivity. The calculated density of states in both cases suggests increased formation of unoccupied orbital states, with prominence of the S 3p orbital states, depicting the capability of synergistic interaction with Sn and C atoms.