950 publications from this institution
Stacking different two-dimensional (2D) atomic layers is a feasible approach to create unique multilayered van der Waals heterostructures with desired properties. 2D materials, graphene, hexagonal boron nitride (h-BN), molybdenum disulphate (MoS2) and graphene based van der Waals heterostructures, such as h-BN/graphene and MoS2/graphene have been investigated by means of Scanning Transmission Electron Microscopy (STEM).
We present a detailed transmission electron microscopy and electron diffraction study of the thinnest possible membrane, a single layer of carbon atoms suspended in vacuum and attached only at its edges. Membranes consisting of two graphene layers are also reported. We find that the membranes exhibit random microscopic curvature that is strongest in single-layer membranes. A direct visualization of the roughness is presented for two-layer membranes where we used the variation of diffracted intensities with the local orientation of the membrane.