van der Waals Screening by Single-Layer Graphene and Molybdenum Disulfide

Abstract

A sharp tip of atomic force microscope is employed to probe van der Waals forces of a silicon oxide substrate with adhered graphene. Experimental results obtained in the range of distances from 3 to 20 nm indicate that single-, double-, and triple-layer graphenes screen the van der Waals forces of the substrate. Fluorination of graphene, which makes it electrically insulating, lifts the screening in the single-layer graphene. The van der Waals force from graphene determined per layer decreases with the number of layers. In addition, increased hole doping of graphene increases the force. Finally, we also demonstrate screening of the van der Waals forces of the silicon oxide substrate by single- and double-layer molybdenum disulfide.

First-Principles Models for van der Waals Interactions in Molecules and Materials: Concepts, Theory, and Applications

“…Substantial understanding can be gained by analyzing the performance of vdW-inclusive methods for cohesive and elastic properties of different solid phases. This applies to 112 vdW interactions by the presence of heterostructured surfaces with complex dielectric profiles. Hence, it seems that it should be possible to design molecular interaction profiles by carefully chosen nanostructures with specific geometries and dielectric properties.…”

Wear properties of graphene edges probed by atomic force microscopy based lateral manipulation

“…Therefore, graphene can be applied as an extremely compact protective coating for friction and wear reduction [2,4,5,6,7,8], as an anti-corrosion layer [9], for van der Waals screening [10], as a lubricant for rotating and sliding electrical contacts [11], for the mechanical encapsulation and protection of molecules and 10 cells [12,13,14,15], and for flexible optoelectronics [16,17,18,19].…”

Physical adsorption at the nanoscale: Towards controllable scaling of the substrate-adsorbate van der Waals interaction

“…This lack of understanding is best exemplified by recent puzzling experimental observations, which include (i) ultralong-range vdW interactions extending up to tens of nanometers into heterogeneous Si/SiO 2 dielectric interfaces [17,18], and influencing the delamination of extended graphene layers from silicon substrate [19]; (ii) complete screening of the vdW interaction between an atomic force microscope (AFM) tip and a SiO 2 surface by the presence of a single layer of graphene adsorbed on the surface [20]; (iii) superlinear sticking power laws for the physical adsorption of metallic clusters on carbon nanotubes with increasing surface area [21]; and (iv) nonlinear increases in the vdW attraction between homologous molecules and an Au(111) surface as a function of the molecular size [22]. Recently, theoretical evidence was found for exceptionally long-ranged vdW attraction between coupled low-dimensional nanomaterials with metallic character [11] or small band gap [10,14].…”