"<i>In situ</i> imaging of layer-by-layer sublimation of suspended grap" by Jian Yu Huang, Liang Qi et al.

Article Title

In situ imaging of layer-by-layer sublimation of suspended graphene

Authors

Jian Yu Huang, Center for Integrated Nanotechnologies (CINT), Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
Liang Qi, Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
Ju Li, Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA

Keywords

Graphene, sublimation, in situ electron microscopy, vacancy hole, bilayer edge

Abstract

An individual suspended graphene sheet was connected to a scanning tunneling microscopy probe inside a transmission electron microscope, and Joule heated to high temperatures. At high temperatures and under electron beam irradiation, the few-layer graphene sheets were removed layer-by-layer in the viewing area until a monolayer graphene was formed. The layer-by-layer peeling was initiated at vacancies in individual graphene layers. The vacancies expanded to form nanometer-sized holes, which then grew along the perimeter and propagated to both the top and bottom layers of a bilayer graphene joined by a bilayer edge. The layer-by-layer peeling was induced by atom sublimation caused by Joule heating and facilitated by atom displacement caused by high-energy electron irradiation, and may be harnessed to control the layer thickness of graphene for device applications.