Field Emission from Graphene Nanosheets

Abstract

Graphene Simulation 140 electron microscope (FE-SEM) system.We will also present our recent progress in miniature sized x-ray tubes with GNS field emitter.The tube has both the lifetime more than 10,000 hours and the stability better than 1 %; therefore, we believe GNS is best suited for field emitters.We will put the x-ray tube into practical use in coming years.Finally (section 7), we will give our future prospects for the GNS field emitter. Fabrication and nanostructure characterizationThe GNS field emitters are fabricated by hydrogen plasma etching of a carbon rod in a microwave (a frequency of 2.45 GHz) plasma chemical vapor deposition equipment as shown in Fig. 1.Typical etching condition is as follows; a microwave power of 800 W, a gas pressure of 1.3 kPa, a H 2 gas flow rate of 80 sccm, a substrate temperature of 600 ˚C, a substrate bias of -200 V, and an etching time of 30 min (Matsumoto & Mimura, 2004;Matsumoto & Mimura, 2005).