Field Emission and Lifetime Characteristics of Titanium-coated Carbon Nanotubes

We investigated the effect of titanium (Ti)-coated carbon nanotubes (CNTs) theoretically and experimentally. We found that adsorption of single Ti atom lowers the work function of CNTs by density functional calculations. Also, Ti-coated CNTs showed the largest increase in local density of states around Fermi level under electric fields. Coating of Ti metal on CNTs was carried out by electroless plating method. Ti-coated CNTs were mixed with conductive pastes, and then screen-printed. The measurement of field emission carried out using a diode structure showed that the electron emission of Ti-coated CNT films uniformly had a field of 3.7 V/mum at a current density of 100 mu/cm
₂
(1/500 duty), as compare to bare CNT films showed a field of 5.5 V/mum. Furthermore, the lifetime of our CNT samples was about a few times as much as that of the pristine ones. Therefore, Ti-coated CNTs improved the characteristics of CNT-based field emission emitters