Low-energy electron transmission imaging of clusters on free-standing graphene

We investigated the utility of free-standing graphene as a transparent sample carrier for imaging nanometer-sized objects by means of low-energy electron holography. The sample preparation for obtaining contamination-free graphene as well as the experimental setup and findings are discussed. For incoming electrons with 66 eV kinetic energy, graphene exhibits 27% opacity per layer. Hence, electron holograms of nanometer-sized objects adsorbed on free-standing graphene can be recorded and numerically reconstructed to reveal the object’s shapes and distribution. Furthermore, a Moiré effect has been observed with free-standing graphene multi-layers. DOI: https://doi.org/10.1063/1.4752717 Posted at the Zurich Open Repository and Archive, University of Zurich ZORA URL: https://doi.org/10.5167/uzh-72362 Accepted Version Originally published at: Longchamp, Jean-Nicolas; Latychevskaia, Tatiana; Escher, Conrad; Fink, Hans-Werner (2012). Lowenergy electron transmission imaging of clusters on free-standing graphene. Applied Physics Letters, 101(11):113117. DOI: https://doi.org/10.1063/1.4752717