Characteristics of carbon nanotubes deposited by using low-temperature atmospheric-pressure plasma-enhanced chemical vapor deposition

In this study, carbon nanotubes (CNTs) were grown using a capillary dielectric barrier discharge (DBD)-type atmospheric-pressure plasma-enhanced chemical vapor deposition (AP-PEOVD) system at a low temperature of 400 °C, and their growth characteristics were investigated. The CNTs grown using He (6 slm)/C ₂H ₂ (90 sccm) AP-PECVD with additive gases (NH ₃, N ₂) for 5 minutes at 400 °C after a pretreatment were multi-layer CNTs with diameter of 20 - 50 nm and uniform lengths of 1.5 - 2 μm. FT-Raman spectroscopy showed that the grown CNTs were multi-wall CNTs with a D-band/G-band intensity ratio of 0.9. Transmission electron microscopy of the AP-PECVDgrown CNTs showed that the CNT had a 30-nm outer diameter and a 7-nm hollow inner diameter with a Ni particle on the top of the tube.