碳纳米管场发射器件放气特性分析及其对场发射性能的影响

发布时间：2018-09-08 12:07

【摘要】：为了研究场发射冷阴极电流跌落机制,采用四极质谱仪实时分析的方法研究了碳纳米管阴极场发射器件的放气特性及工作状态下器件内残余气体对阴极场发射性能的影响.结果表明:碳纳米管阴极场发射器件工作时,放出气体的主要成份是H_2,CO_2,CO;随着阴极发射电流密度的增加,气体成份的分压也随着增加.碳纳米管阴极的场发射性能,例如开启场强、阈值场强和场发射电流密度都与放出气体压强密切相关.碳纳米管阴极在压强为2.1×10~(-3)Pa的残余气体环境下工作1.5 h后,开启场强和阈值场强相应增加了29.4%和50.0%.阴极受残余气体影响,一方面阴极发射材料表面功函数增加;另一方面阴极发射体场增强因子减小.增大的功函数和减小的场增强因子降低了阴极的场发射性能.因此,场发射器件放气是阴极电流跌落的重要原因.
[Abstract]:In order to study the mechanism of field emission cold cathode current drop, the discharge characteristics of carbon nanotube cathode field emission devices and the effect of residual gas in the device on the cathode field emission performance were studied by using a real time quadrupole mass spectrometer. The results show that when the cathode field emission devices of carbon nanotubes work, the main component of the gas emission is H2CO2COG, and the partial pressure of the gas component increases with the increase of the cathode emission current density. The field emission properties of carbon nanotube cathodes, such as open field strength, threshold field intensity and field emission current density, are closely related to the pressure of the released gas. The opening field strength and threshold field strength of the carbon nanotube cathode increased by 29.4% and 50.0% respectively after working in the residual gas environment with a pressure of 2.1 脳 10 ~ (-3) Pa for 1.5 h. The cathode is affected by the residual gas, on the one hand, the surface work function of the cathode emitter increases; on the other hand, the field enhancement factor of the cathode emitter decreases. The field emission performance of the cathode is reduced by increasing the work function and decreasing the field enhancement factor. Therefore, field emission device degassing is an important reason for cathodic current drop.
【作者单位】：南京工程学院数理部;南京师范大学物理科学与技术学院;东南大学电子科学与工程学院;
【基金】：国家自然科学基金(11504167、61674029) 江苏省自然科学基金(BK20141390) 南京工程学院自然科学基金(QKJB201409、CKJC201602)
【分类号】：TN103;TB383.1

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