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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Beyond the Anderson rule: importance of interfacial dipole and hybridization in van der Waals heterostructures

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Besse, Rafael [1, 2] ; Silveira, V, Julian F. R. ; Jiang, Zeyu [1] ; West, Damien [1] ; Zhang, Shengbai [1] ; Da Silva, Juarez L. F. [3]
Total Authors: 6
[1] Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 - USA
[2] Univ Sao Paulo, Sao Carlos Inst Phys, POB 369, BR-13560970 Sao Carlos, SP - Brazil
[3] Silveira, Julian F. R., V, Univ Sao Paulo, Sao Carlos Inst Chem, POB 780, BR-13560970 Sao Carlos, SP - Brazil
Total Affiliations: 3
Document type: Journal article
Source: 2D MATERIALS; v. 8, n. 4 OCT 2021.
Web of Science Citations: 0

Vertical stacking of two-dimensional materials with weak van der Waals (vdW) interactions has laid the ground for breakthroughs in physics as well as in technological applications. Although vdW interactions dominate interlayer binding, interlayer electronic coupling may not be negligible and can lead to properties beyond the superposition of constituent monolayers. Here, studying heterobilayers of transition-metal dichalcogenides (MQ (2); M = Mo, Ni, Pt; Q = S, Se) by means of density functional theory calculations, we show two mechanisms that influence the band gaps of vdW heterostructures beyond the Anderson rule: (1) interfacial hybridization (mainly involving out-of-plane states, such as chalcogen p ( z )-states), which leads to an upshift in the valence band maxima and accordingly a decrease in the band gap. (2) Formation of an interfacial electric dipole, resulting in an effective gap increase in type-II junctions. While the former is material specific, depending on the proximity of p ( z )-states to each other and the valence band maxima, the latter can be generally described using a model based on the charge density decay outside the monolayers and the pristine band edge positions with respect to the vacuum level, irrespective of junction type. (AU)

FAPESP's process: 19/09276-5 - Ab Initio Design of van der Waals Heterostructures
Grantee:Rafael Besse
Support type: Scholarships abroad - Research Internship - Doctorate
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 type: Scholarships in Brazil - Doctorate
FAPESP's process: 17/11631-2 - Computational material science and chemistry
Grantee:Juarez Lopes Ferreira da Silva
Support type: Research Grants - Research Centers in Engineering Program
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 type: Multi-user Equipment Program