Characterization of interlayer forces in 2D heterostructures using neutral atom scattering

Abstract We show that neutral atom scattering is suitable to determine the coupling strength between a two-dimensional (2D) material and the underlying substrate. This information can be obtained from the thermal attenuation of the specular intensity, as well as from angular distributions of He and Ne atoms in the low incident energy (∼50 meV) regime. For graphene (Gr) grown on several metal substrates, there is a direct correlation between the slope of thermal attenuation measurements and the Gr–substrate coupling strength obtained from surface phonons measurements. In addition, Ne scattering presents a broad, classical angular distribution when the Gr–substrate coupling is weak, like in Gr/Ir(1 1 1), whereas sharp diffraction features are observed for strongly interacting systems, like Gr/Ru(0 0 0 1). This makes neutral atom scattering a quick and sensitive indicator of the coupling strength between any 2D material with their substrates. The influence of the moiré superstructures on this simple picture is also discussed.