High Brightness of Field Emitted Electron Beam from Graphene Edges
Jeng-Shiung, Chen1, Tzu-Hua Chen1, Po-Kai, Chiu1, Li Jie,Chen1, Wei Jung, Chen1, Prof. Jeff T. H., Tsai1*
1Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung, Taiwan
* presenting author:Tsung-Hui Tsai, email:thtsai@mail.ntou.edu.tw
We fabricated freestanding graphene edge probes as electron sources and test their field emission properties. The electron beam brightness from such novel electron source were measured. We use solid carbon source to synthesis graphene on copper foil. This copper foil was then rolled and pulled into a structure with the graphene protrusion form the Cu substrate and made the freestanding graphene edge emitter. In order to increase the field emission performance, we use the tungsten wire to heat up graphene at 650 °C. The field emission experiments are performed in our lab-assemble electron beams measure system. This system has three electrodes: The cathode places the emitter. An anode is a metal plate which has a hole attracts electrons through the anode. The phosphorous screen accelerates electron beams to help us to observe the beam patterns. The field emission performance of freestanding graphene edge emitter was comparison with the pure tungsten wire and the pure copper, respectively, in this system. We then utilized a sharp edge of a metal blade to inference the electron beams which came from the graphene edge and we observed the Fresnel interference pattern from such configuration. We then calculated the brightness of this electron beam. After that, we place the blade between the anode and the screen for observed the Fresnel interference pattern when the electron beams through the blade. According to this pattern, the brightness of freestanding graphene edge emitter was determined to 2.2X1010Am-2sr-1V-1.

Keywords: Graphene, Filed Emission, Electron Source