Field emission from few-layer graphene nanosheets produced by liquid phase exfoliation of graphite.
Graphene nanosheets have been synthesized from commercial expandable graphite by heating in a microwave oven and dispersing in ethanol by ultrasonication. Scanning and transmission electron microscopy and electron energy-loss spectroscopy and atomic force microscope showed that the nanosheets were about 2 nm in thickness and 10 microm in diameter. The field emission of the graphene sheets has been investigated. An emission current density of 1 mA/cm2 has been achieved at an electric field of 3.7 V/microm with a turn-on field of 1.7 V/microm at 0.01 mA/cm2. The annealing of the samples at 400 degrees C in vacuum greatly improved the field emission performance.
National Laboratory for Vacuum Electronics, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, China.
Jianhui
J
Dong
Baoqing
B
Zeng
Yucheng
Y
Lan
Shikai
S
Tian
Yun
Y
Shan
Xingchong
X
Liu
Zhonghai
Z
Yang
Hui
H
Wang
Z F
ZF
Ren