Novel planar field emission of ultra-thin individual carbon nanotubes

Abstract

In this work, we proposed and realized a new prototype of planar field emission devicebased on as-grown individual carbon nanotubes (CNTs) on the surface of a Si–SiO2 substrate. The anode, cathode and the CNT tip all lie on the same surface, so the electronemission is reduced from three-dimensional to two-dimensional. The benefits of such adesign include usage of thinner CNT emitters, integratability with planar technology, stableconstruction, better heat dissipation, etc. A tip-to-tip field emission device was presentedbesides the tip-to-electrode one. Real-time, in situ observation of the planar field emissionwas realized in a scanning electron microscope (SEM). Measurements showed that theminimum voltage for 10 nA field emission current was only 8.0 V and the maximumemission current density in an individual CNT emitter (1.0 nm in diameter) exceeded5.7 × 108 A cm−2. These results stand out in the comparison with recent works on individual CNTfield emission, indicating that the planar devices based on ultra-thin individualCNTs are more competitive candidates for next-generation electron field emitters.