Synthesis of crystalline carbon nanotube arrays on anodic aluminum oxide using catalyst reduction with low pressure thermal chemical vapor deposition

Well-aligned crystalline carbon nanotubes (CNTs) were synthesized on anodic aluminum oxide (AAO) template using lowpressure thermal chemical vapor deposition (TCVD). The AAO templates were fabricated using an anodization process, and Fe as a catalyst was electrochemically deposited inside the bottom of the pores on the AAO template. For promotion of catalytic reaction of Fe, pore widening and catalyst reduction were performed. The enhancement of the catalytic reaction between C ₂H ₂ and the Fe catalyst particles results in CNTs with good crystallinity and a high packing density without the deposition of amorphous carbon on the pore surface of the AAO templates. The diameter and density of the CNTs were approximately 50 nm and 7 × 10 ⁹ CNTs/cm ² (70% of pore density), respectively. When the threshold voltage of the electron emission was measured with a gap of 300 μm, it showed a very low turn-on field of 0.87 V/μm and the field enhancement factor was greater than 5600.