High-performance N_2O plasma treated multiwall carbon nanotubes grown by thermal chemical vapor deposition

摘要

In this paper, the effects of N_2O plasma post-treatment on field emission properties of multi-walls carbon nanotubes (MWCNTs), which were fabricated by thermal chemical vapor deposition (CVD) method on silicon substrates, were studied. The surface morphologies of the MWCNTs before and after N_2O plasma post-treatment were investigated by scanning electron microscopy (SEM) and Raman spectrum. The emission properties of the untreated MWCNTs and that of treated ones were measured. A N_2O plasma post-treatment process was performed to etch the surface of MWCNTs and modify the density of MWCNTs and dope nitrogen atoms into MWCNTs in high density plasma chemical vapor deposition (HDPCVD) system. The experimental results show improved field emission properties under proper plasma conditions. The turn-on electric field decreased from 2.5 to 1.7 V/μm, and the emission current density increased from 200 to 889 μA/cm~2 at an applied field of 4.8 V/μm.