Abstract Submitted to the    NANOTUBE'04 Conference:

In the applications of carbon nanotubes (CNTs) for lighting and display, field emission properties are affected significantly by the density of CNT emitter. In order to avoid the screen effect, low density of carbon nanotubes (CNTs) for field emission display is required. In this work, low density CNTs can be synthesized by controlling the precipitation of catalyst on metal substrate. Catalyst and metal film with the thickness of several and several tens nm, respectively, were coated on SiO2 substrate by DC sputter. Different grain sizes can be obtained by controlling the annealing and cooling processes. Catalyst with the size of several nanometers can be formed at the triple junction between three grains. The synthesized nano-sized catalysts were then adopted as the growth site of CNTs in a rapid-annealing-cooling system. Microstructure of the synthesized CNTs was examined by SEM and HRTEM, and the images revealed that thin walled CNTs can be derived in this process. Moreover, field emission properties were measured to investigate the influence of CNT density on the electron emission properties