Growth temperature effect on field emission properties of printable carbon nanotubes cathode

The carbon nanotubes (CNTs) were synthesized by low pressure chemical vapor deposition (CVD) in the temperature range of 500–750 °C. The dependence of field emission properties of screen-printed cathode on the CNTs growth temperatures was studied. The scanning electron microscope (SEM) images and Raman spectra showed that with the temperature increasing from 500 °C to 750 °C, the average diameter of most CNTs decreased, and the crystallinity of the nanotubes increases as shown by the narrower and more intense G peak in the Raman spectra. It is found that the higher growth temperature, the better field emission properties of the screen-printed nanotubes cathodes, i.e. lower turn-on emission field, higher emission current and more uniform emission.