Modeling the electron field emission from carbon nanotube films

A theoretical framework for the electron field emission from carbon nanotub es (CNTs) is discussed. Using the tunneling theory, the influence of the de tailed electron energy dispersion is proven to be of little importance for the electron field emission. By means of numerical computations in a simpli fied model, the influence of the environment on the local field on a CNT is discussed for an aligned CNT film. In a simple triangular model for the po tential energy barrier at the tube end, a tunneling probability was obtaine d. A statistical model was developed for the structural and functional para meters of aligned CNT films. Practical CNT films of excellent alignment, ob tained directly on a tungsten wire by plasma-enhanced chemical vapor deposi tion, were analyzed by this statistical model. Their distribution in the en hancement factors was thus deduced. An indirect method to get the average e lectrical parameters of the film using only a limited amount of experimenta l data was thus established. (C) 2001 Elsevier Science B.V. All rights rese rved.