中国物理B ›› 2013, Vol. 22 ›› Issue (6): 68504-068504.doi: 10.1088/1674-1056/22/6/068504
• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇 下一篇
王金婵
Wang Jin-Chan (王金婵)
摘要: In this paper, a vacuum system is employed to compare the emission stabilities of the same ZnO cathode in a sealed field emission (FE) device and under ultrahigh vacuum (UHV) condition. It is observed that the emission current is more stable under the UHV level than that in the device. When all conditions except the ambient gases are kept unchanged, the emission current degradation is mainly caused by the residual gases in the sealed device. The quadrupole mass spectrometer (QMS) equipped on the vacuum system is used to investigate the residual gas components. Based on the QMS data obtained, the following conclusions can be drawn: the residual gases in ZnO-FE-devices are H2, CH4, CO, Ar, and CO2. These residual gases can change the work function at the surface through adsorption or ion bombardment, thereby degrading the emission current of the cathode.
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