Stacking Order Effects on the Electronic and Optical Properties of Graphene/Transition Metal Dichalcogenide Van der Waals Heterostructures

Author(s)

Silveira, V, Julian F. R. ; Besse, Rafael ^[1] ; Da Silva, Juarez L. F. ^[2]

Affiliation

^[1] Univ Sao Paulo, Sao Carlos Inst Phys, BR-13560970 Sao Carlos, SP - Brazil

^[2] Silveira, Julian F. R., V, Univ Sao Paulo, Sao Carlos Inst Chem, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: ACS APPLIED ELECTRONIC MATERIALS; v. 3, n. 4, p. 1671-1680, APR 27 2021.
• Web of Science Citations: 0

Abstract

Multilayered van der Waals (vdW) vertical heterostructures are a promising avenue for combining different two-dimensional materials to achieve desirable properties for numerous optoelectronic applications. To improve our understanding of how the stacking order can affect the physical properties of these systems, we present a density functional theory study of the energetic, electronic, and optical properties of vdW heterostructures of graphene (Gr)-transition-metal dichalcogenides (TMDs), namely, monolayer (graphene, MoS2, and WS2), bilayer, and tetralayer systems. We found that the Gr-TMD interactions are dominated by mainly vdW interactions, while the TMD-TMD systems also display a weak hybridization contribution of out-of-plane orbitals, which enhances the binding energy. An analysis of the bilayer electronic structure reveals that a stronger interaction induces small band gap deviations from Andersons rule. Thus, the key effect of the stacking order in tetralayer systems is primarily to control the level of interaction between TMD layers, thereby controlling the TMD band gap. The application of pressure in the direction of layer stacking can intensify this effect, as it affects the degree of interaction between TMD layers. The optical response can be well described by the sum of the response of the individual monolayers; however, minor effects were noticeable upon application of external pressure, particularly in the 3-4 eV range. Based on this, we can employ both the stacking order, controllable via growth conditions of the material, as well as pressure to control the interaction between layers and thereby tune the electronic properties of multilayered vdW heterostructures to suit various applications. (AU)

• FAPESP's process: 17/09077-7 - Ab-initio study of the structural, electronic, and optical properties of van der Waals heterostructures
• Grantee: Rafael Besse
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 18/21401-7 - Multi-User Equipment approved in grant 2017/11631-2: cluster computational de alto desempenho - ENIAC
• Grantee: Juarez Lopes Ferreira da Silva
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 17/11631-2 - CINE: computational materials design based on atomistic simulations, meso-scale, multi-physics, and artificial intelligence for energy applications
• Grantee: Juarez Lopes Ferreira da Silva
• Support Opportunities: Research Grants - Research Centers in Engineering Program