Observation on CNT-FED under various vacuum levels and calculation on number of electron-gas collisions
Based on experimental observation and theoretical analysis, it explicates that light emission of a carbon nanotube-field emission display (CNT-FED) is mainly caused by electron bombardment on the phosphour if the level of vacuum ranges from 10(-4) to 5 Pa. In this case, light emission of the phosphour excited by ultraviolet (UV) light derived from gas discharge cannot be observed. If vacuum level is greater than 5 Pa, no emitted light is observed, since a large amount of gas ionisation reduces the electric potential difference between the cathode and the anode. To analyze collision between electron and gas under field emission conditions, a mathematical and physical model was built. Based on this model the number of electron-gas collisions is calculated. Calculations results indicate that the product of gas pressure and distance between the electrodes (pd) is a better parameter to characterize the effect of vacuum level for FED than gas pressure only. Calculations results also show that if the distance between the cathode and the anode is increased, it should be to improve the vacuum level to obtain the same effect. (C) 2006 Elsevier B.V. All rights reserved.
vacuum level electron-gas collision field emission carbon nanotube