摘要
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.
基金
This work was performed,in part,at the Center for Integrated Nanotechnologies,the U.S.Department of Energy,Office of Basic Energy Sciences user facility.Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation,a Lockheed-Martin Company,for the U.S.Department of Energy under Contract No.DE-AC04-94AL85000
JL would like to acknowledge support by Honda Research Institute USA,NSF CMMI-0728069,AFOSR,and ONR N00014-05-1-0504
J.Y.H.would like to thank Dr.Ping Lu at Sandia National Laboratories for conducting the HRTEM image simulations.
