Improvement in electron emission from carbon nanotube cathodes after Ar plasma treatment

Abstract

Carbon nanotube (CNT) cathode surfaces have been exposed to Ar plasma and the emission characteristics were measured. When a CNT cathode was exposed to Ar plasma for 3 min, the emission characteristics were improved. The emission current increased after an Ar plasma treatment for 3 min by three orders of magnitude from 9.0×10−5 to 3.3×10−1 mA/cm2 at 4.0 V/μm with a decrease in turn-on voltage from 3.3 to 1.7 V/μm. According to scanning electron microscopy images, entangled CNT bundles were raveled out by Ar plasma treatment.