Abstract
This thesis investigates the field emission characteristic of periodic arrays of vertically aligned isolated carbon nanotubes (CNTs) coated by boron nitride (BN) using magnetron sputtering method and plasma-assisted chemical vapor deposition method. It has been reported that BN film could be one of the promising materials for field emitter because of its negative electron affinity (NEA) at the surface. In addition to its high aspect ratio, the field emission characteristics of CNTs have been widely studied due to its chemically and mechanically robust properties. The synergism of the combination of these two materials on the field emission mechanisms was investigated in this work. Vertically aligned CNTs were synthesized using catalytic chemical vapor deposition (CCVD) method to avoid screen effects due to high density of CNTs. After that, the periodic arrays of vertically aligned isolated CNTs coated with BN film were fabricated. The comparison between those with and without BN coating revealed a significant effect of the thickness and the NEA characteristics of BN coating on the field emission properties. The electron pathway and the field emission mechanisms of BN coated CNTs will be further discussed.