Very High Field-Emission Current From a Carbon-Nanotube Cathode With a Pulse Driving Mode

Carbon-nanotube (CNT) cathode has promising applications in high-frequency electron and display devices due to its good field-emission performance. The field-emission performance of CNTs with a pulse driving mode is studied both by theoretical analysis and experiments. The impulse responses of a field-emission diode with different external resistance and input voltage are investigated. From the simulations and experiments, it can be seen that the large external resistance and small input voltage can keep a stable field emission. However, it limits the peak value of pulse field-emission current. With a proper external resistance, a very high field-emission current of 2 A (current density is 8 A/cm²) is obtained with 50-ms pulsewidth and 1 : 50 duty cycle. The experimental results also show that the uniformity of field emission is improved obviously in a pulse driving mode.