Field emission properties of laser ablated multi-walled carbon nanotubes

Abstract

In the present study, the field emission properties of multi-walled carbon nanotubes (MWCNTs) treated with laser ablation have been investigated. The MWCNTs were synthesized by chemical vapor deposition method. The laser ablation treatment was performed in liquid medium for laser ablation time of 40 min and 60 min. The morphology of MWCNTs films was characterized by using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The results exhibit that the field emission properties of MWCNTs are dependent on the laser ablation time. The Raman spectra of laser-ablated MWCNTs clearly showed disorder and increase in graphitic content. The SEM and TEM results clearly revealed the separation of MWCNTs after laser ablation treatment. The field emission characteristics of the MWCNTs showed that the turn-on fields and current density are improved for the nanotubes treated with laser ablation. The enhancement in the field emission characteristics of MWCNTs is attributed to the disorder as well as the increase in the aspect ratio which causes more pathways for electron emission.