Hot-filament CVD Growth of Vertically-aligned Carbon Nanotubes on Support Materials for Field Electron Emitters

Abstract

Carbon nanotubes are used in applications such as energy storages, electronic devices. For these applications, direct assembly of the well aligned and densely packed CNTs (VACNTs) on electrically conducting substrates is of interest. In this paper, we report a direct growth of the VACNTs on several substrates by using hot-filament chemical vapor deposition (hot-filament CVD) and a catalytic buffer-layer structure. The buffer layer was the Aluminum (Al) thin film used together with iron (Fe) as the catalyst. It was found that the underneath layer (Al) was critical for obtaining the VACNT forests with high purity and good contact. The as-fabricated VACNT/support-material structures are object to test field electron emission properties. Testing results of the VACNT samples demonstrated promising field emission characteristics in term of high emitting currents.