Abstract
Carbon nanotube field emission display is one of the hot applications of carbon nanotube(CNT). For solving the package problem, we should directly grow well aligned-CNTs on the glass substrate.In large-area field emission display applications where high stress point glass substrate is used for vacuum-sealed packaging and low cost considerations, the CNTs synthesis temperature lower than the stress point of ~ 570℃ is required. In the thermal CVD processes, the catalyst passivation due to the slow carbon diffusion rate limiting and the consequent amorphous carbon formation on the catalyst surface was considered to be the main reason hampering carbon nanotube growth at the low temperature. The amount of amorphous carbon decreases apparently with the decrease of the process pressure for the low temperature growth of CNTs. In this approach, we report a successful synthesis of vertically aligned-MWNTs on Ni / Cr coated glass (PD200) substrate at 550 0C and 500 0C by low pressure (8 torr) thermal CVD with reasonably good field emission characteristics of ~ mA/cm2 emission current density.By the F-N equation analysis, the turn-on voltage is 4.61 V / μm at the 550℃ growing CNTs and 6.15 V / μm at the 550℃ growing CNTs. From the high resolution trasimission electronic microscopy (HRTEM), we show the nearly hollow structure at our low pressure-temperature CNTs.We also repeat the parameter of growing CNTs on the 2 x 8 cm2 large glass substrate to prove this kind of CNTs can be the well emission source on the applications of field emission display.