Field Emission Damage Modes of Carbon Nanotube Spindt Cathode Arrays

The field electron emission of carbon nanotubes has been heavily studied over the past two decades for various applications, including display technologies and spacecraft propulsion. However, a commercializable, lightweight and internally gated electron source has yet to be realized. Electrical shorting of the gate to the substrate from arcing between electrodes is a common and problematic failure mode for Spindt-type carbon nanotube electron sources, causing catastrophic damage and severely limiting their manufacturability. Other types of damage and degradation include physical damage to the carbon nanotubes and their disconnection from the substrate. This work explores field emission damage and its effects on failure in a uniquely designed Spindt-type carbon nanotube cathode. Eighty samples are fabricated and characterized for field emission performance. Analysis of the tested samples reveals three distinct types of damage to the emission pits.