Fabrication of carbon nanoneedle and carbon nanowall mixture film with two-step growth method

A novel nano-carbon electron emitter film has been developed on a stainless steel substrate by a direct current plasma chemical vapor deposition system. Samples grown at temperatures of 900 °C and 1100 °C showed different surface morphologies. It is found that a two-step growth process established by combining these two temperature growths together is suitable for deposition of a high density emitter array film. The as-grown nano-carbon film indicates a carbon nanoneedle and carbon nanowall mixture film, where the needle array density is about 3 × 107/cm2. The I–V characteristic shows an emission current density of 228 mA/cm2 at 2.5 V/μm, and the field emission current is stable, making it possibly suitable for developing field emission devices.