Field emission from carbon nanotube Mat

Abstract

Field emission characteristics of both top and bottom surfaces of carbon nanotube mats (CNT-Mats) or sheet-like CNTs were investigated. The emission characteristics of the CNT-Mat were compared with those of screen-printed CNT emitters before and after UV laser irradiation. Screen-printed CNT emitters have very low emission current density without proper surface treatment, although after UV laser irradiation, the emission current densities increased drastically. On the other hand, the CNT-Mats have excellent field emission characteristics even without any surface treatment. With an applied electric field of 3.47 V/μm, the emission current density of the top surface of CNT-Mat reached 1.99 mA/cm2, which was six times higher than that of screen-printed CNT emitters after UV laser irradiation. The field emission stability of CNT-Mat and screen-printed CNT emitters in various pressures were also investigated. Both CNT emitters have stable field emissions at and below 1×10−4 Pa.