Electron-induced rippling in graphene.

Low-energy electron point projection microscopy of suspended graphene, the ultimate ‘microscope slide’

Point projection microscopy (PPM) is used to image suspended graphene by using low-energy electrons (100–205 eV). Because of the low energies used, the graphene is neither damaged nor contaminated by the electron beam for doses of the order of 107 electrons per nm2. The transparency of graphene is measured to be 74%, equivalent to electron transmission through a sheet twice as thick as the cova...

Rippling ultrafast dynamics of suspended 2D monolayers, graphene.

Here, using ultrafast electron crystallography (UEC), we report the observation of rippling dynamics in suspended monolayer graphene, the prototypical and most-studied 2D material. The high scattering cross-section for electron/matter interaction, the atomic-scale spatial resolution, and the ultrafast temporal resolution of UEC represent the key elements that make this technique a unique tool f...

Electric field-controlled rippling of graphene.

Metal-graphene interfaces generated by electrode deposition induce barriers or potential modulations influencing the electronic transport properties of graphene based devices. However, their impact on the local mechanical properties of graphene is much less studied. Here we show that graphene near a metallic interface can exhibit a set of ripples self-organized into domains whose topographic ro...

Entropic effects of thermal rippling on van der Waals interactions between monolayer graphene and a rigid substrate

Thermomechanics of monolayer graphene: Rippling, thermal expansion and elasticity

Thermomechanical properties of monolayer graphene with thermal fluctuation are studied by both statistical mechanics analysis and molecular dynamics (MD) simulations. While the statistical mechanics analysis in the present study is limited by a harmonic approximation, significant anharmonic effects are revealed by MD simulations. The amplitude of out-ofplane thermal fluctuation is calculated fo...