Efficient field emission from triode-type 1D arrays of carbon nanotubes

Carbon nanotube(CNT) emitters were formed on line-patterned cathodes in microtrenches through a thermal CVD process. Single-walled carbon nanotubes(SWCNTs) self-organized along the trench lines with a submicron inter-CNT spacing. Excellent field emission(FE) properties were obtained: current densities at the anode (J_a) of 1νAcm^-2, 10mAcm^-2 and 100mAcm^-2 were recorded at gate voltages (V_g) of 16, 25 and 36V, respectively. The required voltage difference to gain a 1:10 000 contrast of the anode current was as low as 9V, indicating that a very low operating voltage is possible for these devices. Not only a large number of emission sites but also the optimal combination of trench structure and emitter morphology are crucial to achieve the full FE potential of thin CNTs with a practical lifetime. The FE properties of 1D arrays of CNT emitters and their optimal design are discussed. Self-organization of thin CNTs is an attractive prospect to tailor preferable emitter designs in FE devices.