Fabrication of wrinkled carbon nano-films with excellent field emission characteristics

B-doped nano-structured carbon films were deposited on Si substrates by means of chemical-vapour-deposition with 3.8-kW microwave-plasma. Scanning electron microscope images show that the deposited films were composed of wrinkled graphitic nano-sheets with considerable disorder structures. Field emission (FE) characteristics measured from such films yielded considerably high FE currents, being larger than 50 mA/cm² at a macroscopic electric field of 9.5 V/μm. A possible mechanism of the observed FEs is discussed in relation to a modified Fowler–Nordheim equation considering field-dependent parameters. As a result, it is found that the structure of the surface geometry mainly increased the FE current densities. Adding a suitable amount of B-component gas to the carbon source gas resulted in a considerable increase in the FE areas of the wrinkled carbon nano-films.