Synthesis of well-aligned thin multiwalled carbon nanotubes on the silicon substrate and their field emission properties

Abstract

Well-aligned multi-walled carbon nanotubes (MWCNTs) were successfully synthesized by catalytic chemical vapor deposition using a hydrogen sulfide (H2S) additive onto Al/Fe thin film deposited on Si wafers. Transmission electron microscopy images indicated that the as-grown carbon products were thin MWCNTs with small outer diameters of less than 10 nm. H2S plays a key role in synthesizing thin MWCNTs with a large inside hollow core. The well-aligned thin MWCNTs showed a low turn-on voltage of about 1.1 V/μm at a current density of 0.1 μA/cm2 and a high emission current of about 1.0 mA/cm2 at a bias field of 2.3 V/μm. We suggest a possible growth mechanism for the well-aligned thin MWCNTs with a large inside hollow core.