Field enhancement factor for an array of MWNTs in CNT paste

The simulation results of the electric field intensity and the enhancement factor gamma, for an individual CNT imaged as a conducting rod is presented. The field enhancement factor <(gamma)over bar >, for the CNT paste array is evaluated experimentally by varying the cathode-anode (CA) spacing, d. The simulations indicate that the distribution of electric field intensity and the enhancement factor as a function of cathode-anode spacing, d, could be divided into the two parts: strong ( d < 100 mu m) and weak ( d > 100 mu m) dependences of the enhancement factor gamma(d). Furthermore, the field enhancement factor, <(gamma)over bar >, estimated experimentally for the CNT paste FEA indicates that the two-region field emission model (TRFE) is adequate for estimation of the field enhancement factor, <(gamma)over bar >. Moreover, the effective enhancement factor, <(gamma)over bar >, for the CNT paste FEA was found to be approximate to 50 gamma and is attributed to the additions of the emission currents from the individual CNTs in an array. In addition, the empiric functions of the geometrical enhancement factor, <(beta)over bar >(d), and <(gamma)over bar >(d) were estimated from the Fowler - Nordheim plot for the CNT paste FEA. One can use the empiric functions <(beta)over bar >(d) and <(gamma)over bar >(d) for the design and fabrication of the devices based on the CNT paste FEA with a variable CA spacing.