太赫兹源场致发射电子源

Field emission electron source for terahertz source application

通过粒子模拟(PIC)软件模拟计算了在ps级别下二极与三极结构碳纳米管场致发射的电流密度与电子注聚焦性能。阳极电压在2kV时,二极结构下电流密度达到1.85A/cm2;三极结构下,栅压700V时发射电流密度达到2.3A/cm2,且在一定的三极结构参数与电极电压下,可以获得较好的电子注聚束效果。通过碳纳米管二极管发射实验,获得了6.6A/cm2的发射电流密度,总发射电流达到52.1mA,可以为太赫兹器件提供连续发射的电子注。

Field emission from carbon nanotube （CNT） has been simulated by a particle-in-cell （PIC） software at pico-second level. The emission current, current density and focus character of a CNT cathode have been discussed. In a diode configuration, the emission current from cathode reaches 1.85 A/cm2 when the anode voltage is 2 kV. While in a triode configuration, the current reaches 2.3 A/cm2 for a gate voltage of 700 V, and the focus performance of electron beam can be optimized by modifying triode parameters and voltage applied to the electrodes. A diode structure with CNT cathode has been fabricated to verify large-current field emission, a total emission current of 52.1 mA and a current density of 6.6 A/cm2 have been obtained from this diode. It proved that field emission cathode can be applied in terahertz source devices.