Field Emission Properties Of Silicon Nanocones, Carbon Nanotubes And Graphene

Field emission is cold cathode electron emission. It can be widely used in flay display devices, X-ray tubes and electron microscopes, etc. In this paper, field emission properties of Si nano-cone arrays, carbon nanotubes and graphene were investigated in three sections.Field emission properties of ion-sputtering induced Si nano-cone arrays were investigated. It was found that the current density was stable for24hours. The maximum fluctuations of current density are about6.2%. XRD spectra of the Si nano-cone arrays showed that there were silicides at the apexes of the nano-cone arrays. These silicides protected Si nano-cone arrays, reduced work function, increased the electron density of states (DOS) at the Fermi level (EF), and reduced gas absorption. Thus, field emission properties of Si nano-cone arrays were improved.Carbon nanotube films were treated by YAG laser with wavelength of1064nm, pulse width of Ins, repetition of10Hz and power of120mW and300mW, respectively. It was found that laser treatment can increase defects in carbon nanotubes, can evaporate the organic adhesions on the films and increase field emission sites effectively. Therefore, field emission properties of carbon nanotube films can be improved. In addition, field emission properties from carbon nanotube films treated by electrolytic solution were investigated at low temperature. The results showed that the turn-on field increased and the current density decreased as temperature decreased. The calculated results showed that the work function increased with decreasing temperature.Field emission properties of graphene films treated by normal pressure and temperature N2plasma were investigated. It was found that the post-treatment can increase defects of graphene films and thus improve the field emission properties. Furthermore, field emission properties of graphene films treated by plasma at low temperature were investigated. It was found that the results were not in correspondent with F-N theory but in good agreement with semiconductor field emission theory. In addition, by using the screen-printed graphene films as cathode, fabricating cathode pattern, and making a diode structure field emission device, static field emission display of images was realized.