碳纳米管场发射电子源的仿真设计与性能测试

Experimental and Simulation Design on Characteristic of CNTs Field Emission Electron Source

碳纳米管(Carbon Nanotubes,CNTs)因其优异的电学性能和大长径比被广泛用作电子源阴极材料。CNTs具有高稳定性和长寿命等特点,广泛应用于高压电极电真空器件中。CNTs电子源采用MEMS(Micro-Electro-Mechanical System)工艺,有助于质谱分析元件、电离真空计、微推力推进器等真空元器件的微型化。设计了一种基于碳纳米管的带有气体进样和离子传输通道的三电极场发射电子源,可为MEMS质谱离子源提供电子束。通过仿真分析和实验测试,研究了栅极结构和馈电参数对场发射性能的影响规律。仿真分析最大场发射阴极电流为46.085μA,电子透过率为64.28%;实验测试最高场发射电流密度为1.62 A/m^(2),电子透过率为75.34%。

Carbon nanotubes(CNTs)are widely used as cathode materials for electron sources due to their excellent electrical properties and large aspect ratio.Benefiting from the high stability and long lifetime of CNTs,they are favored in electro-vacuum devices with high-voltage electrodes.The application of MEMS(Micro-Electro-Mechanical System)technology in the CNTs electron source facilitates the miniaturization of vacuum components such as mass spectrometry,ionization vacuum gauges,and micro thrusters.In this paper,a CNTs based three-electrode field emission electron source with gas injection and ion transport channels is designed,which can provide electron beam for ion source of MEMS mass spectrometry.Through simulation analysis and experimental test,the influence law of the gate structure and electric parameters on the field emission performance is studied.In the simulation analysis,the maximum field emission cathode current is 46.085μA,and the electron transmittance is 64.28%;in the experimental study,the highest field emission current density is 1.62 A/m^(2),and the electron transmittance is 75.34%.