Optimization of screening and emitter density for an array of carbon nanotube field emitters

In order to exploit the high current carrying capacity of Carbon Nanotubes (CNTs), it is important to maximize current density J by controlling screening as well as the emitter density. A model is developed in MATLAB to calculate the current density from an array of nanotube bundle staking into account both the effect of screening and the emitter density in the framework of standard Fowler-Nordheim (F-N) theory. The results obtained indicate that field emission can be optimized when the inter bundle distance is comparable with the nanotube height. Field emission measurements carried out on vertically aligned CNT bundles grown on patterned substrates give a strong support to the results obtained by simulation. (author)