Robust quasi-ohmic contact against angle rotation in noble transition-metal-dichalcogenide/graphene heterobilayers

Abstract

Stacked 2D crystals provide great possibilities to achieve desired functionalities with varying thickness and composition properties. In this work, the electronic properties of heterobilayers of noble transition-metaldichalcogenide (PdS 2 , PtS 2 )/graphene with interlayer rotation angles are systematically investigated by density functional theory calculations. The two layers are combined by weak van der Waals interactions. Each component preserves its band structure in the hybrid system. A charge transference occurs at the interface of the bilayers leading to p-type doping for graphene and n-type doping for PdS 2 (PtS 2 ).Schottky barriers ranging from 0 eV to 0.057 eV appear in both heterobilayers with different orientations between the two monolayers. These results suggest that PdS 2 (PtS 2 )/graphene heterobilayers have quasi-ohmic contact against interface angle rotation.

Study on electronic and optical properties of the twisted and strained MoS2/PtS2 heterogeneous interface

“…Using the Generalized Lattice Match method, the calculated rotation angle ( ), lattice constant (a), mean absolute strain on the MoS 2 layer ( ) and surface distance between two layers (d) are listed inTable 1. For MoS 2 /PtS 2 heterogeneous interfaces, the interface distance is about 3.41 , which is close to those of the van der Waals structure in references[17][18][19]. The change of interlayer distance in the twisting MoS 2 /PtS 2 heterogeneous interfaces generates relatively weak effect, which is very close to recent DFT calculation results on TMDs and nTMDs heterogeneous interfaces[17][18][19].…”

“…For MoS 2 /PtS 2 heterogeneous interfaces, the interface distance is about 3.41 , which is close to those of the van der Waals structure in references[17][18][19]. The change of interlayer distance in the twisting MoS 2 /PtS 2 heterogeneous interfaces generates relatively weak effect, which is very close to recent DFT calculation results on TMDs and nTMDs heterogeneous interfaces[17][18][19]. To analyze the interlayer interaction in the heterogeneous interfaces, MoS 2 units in the heterogeneous interfaces.…”

“…Our calculations show that the mean absolute strains on the MoS 2 or PtS 2 surfaces are 6.97% or 6.31% respectively, which possibly induces the instability of the original atom layers because of a big mismatch strain. In prior studies, the mismatch strains were usually less 2%-3% and the biggest mismatch strain was 5% [18,19,33]. The twisting angles of 19…”

“…MoS 2 /PtS 2 heterogeneous interfaces by the first principle methods, which has been widely used in many previous studies for bilayer structures [14,[17][18][19][21][22][23][24].…”

“…For example, a near 1.1 o twisted graphene sheets show an unconventional superconductivity in 2D superlattices [5,14], a mirrored Dirac cones are observed in the 30 o twisted bilayer graphene [15,16]. The van der Waals (vdW) interaction is reported to affect the electronic properties of twisted MX 2 /MoS 2 heterogeneous interfaces [17,18], and the PdS 2 (PtS 2 )/grapheme heterogeneous interfaces have been confirmed by the quasi-ohmic contact with twisting angles [19].…”