Carbon nanotube pillar arrays for achieving high emission current densities

We introduce an innovative geometry carbon nanotube (CNT) field emitter array capable of achieving stable and high current densities. Arrays of toroid CNT pillars were grown directly on bulk metal alloy substrates and on patterned metal catalyst on silicon substrates. Compared to a solid CNT pillar array (CPA), this toroid CPA (tCPA) provides a larger edge area for achieving a higher stable current density of 50 mA/cm2 at an applied dc field of less than 8 V/μm. Electrostatic simulation data confirming the field enhancement at the inner and outer edges of the tCPA are also presented.