The comparison of photoemission and filed emission properties of double-walled carbon nanotubes and single-walled carbon nanotubes

Abstract

We have investigated photoemission and field emission characteristics of high purity double-wall carbon nanotubes (DWCNTs) synthesized by arc discharge in an hydrogen ambient using a mixture of Fe catalyst and FeS promoter. For comparison with single-wall carbon nanotubes (SWCNTs), high purity SWCNTs was also synthesized. The photoemission spectra show the DWCNTs have a higher binding energy of C-1s level due to the interlayer and a slightly lower intensity than those for the SWCNTs. From the results of photoemission and field emission properties of DWCNTs and SWCNTs, the higher turn-on field of DWCNTs compared with SWCNTs was caused by lower electric DOS of valence bands near Fermi level.