Investigation of growth properties of patterned and aligned carbon nanotubes for field emitter

We demonstrate the use of microstructures as an inducement for the growth of patterned and aligned carbon nanotubes (CNTs) during thermal chemical vapor deposition process. The growth of individual nanotube lines of vertical-standing 8-10 μm length can be controlled in almost any directions. In directions of approximate 90°, 60°, 45° or 0° relative to substrate surface, kinds of aligned CNTs patterns were synthesized. We also show that the flow of carrier gas and apical dominance like plant growth are the main factors of patterning CNTs, which indicates that the distribution of electric field can be controlled and the shielding effects can be weakened. The result establishes a method of patterned and aligned nanotubes, which is well suited for ordered arrays of CNTs field emitters. The field emission currents were observed to be fairly reproducible ranging from 375 to 1000 V and field emission measurements show a low turn-on field (1.25 V/μm).