Low Energy Electron Point Source Microscopy of Two-Dimensional Carbon Nanostructures

Abstract

Abstract 1 nm thick carbon nanomembranes (CNMs) are investigated with Low Energy Electron Point Source (LEEPS) microscopy. A CNM consists of a freely suspended carbon film made from a cross-linked self-assembled monolayer (SAM). During thermal annealing the CNM transforms into nanocrystalline graphene.We determined the electron transmissivity of CNMs from the LEEPS images. After pyrolysis, the LEEPS images showed clear differences compared to pristine CNMs. Upon annealing above 800 ºC the LEEPS images exhibit distinct features that are related to the structural transition. A comparison of LEEPS images with transmission electron micrographs of the same regions and features demonstrates that both microscopic techniques reveal similar structural features.