Ultra-Low-Threshold Field Electron Emission from Pillar Array of Aligned Carbon Nanotube Bundles

Abstract

We observed the field electron emission of the technologically useful current density of 10 mA/cm 2 at an extremely low threshold electric field ( E th ) of 1.0 V/µm, from an array of pillars of aligned carbon nanotube bundles, which were grown on a Si substrate by thermal chemical vapor deposition. Adjusting the distance between the neighboring pillars ( R ) and the pillar height ( H ) to the optimal condition ( R / H = 2) can effectually enhance the field concentration, resulting in a highly efficient electron emission. The obtained E th is 1/2–1/3 times lower than the best values that have been reported to date.