Simulation of field emission current uniformity of low-density freestanding CNT array

Field electron emission (FEE) from carbon nanotube (CNT) array has been widely studied, but improving the uniformity of emission current from a CNT emitter array remains a challenge. In this paper, the uniformity of a freestanding CNT array is simulated. Field enhancement factor (β), electrical field strength at the tip and emission current density of CNTs is calculated. A simple ballast resistor array, like the resistor layer in conventional Spindt cathodes, is utilized. The voltage drops on the resistors and the emission currents form corresponding CNTs are also calculated. Simulation results show that to achieve a reasonable total emission current, emission current from individual CNTs with ballast resistor are much lower than the current from a favorable CNT without the ballast resistor.