Field Emission from Nanostructured Carbon Films on Si Tips

Nanostructured carbon thin films on Si tips were prepared by hot filament chemical vapour deposition at different substrate temperatures. The Si tips and films were obtained under various deposition conditions in the same reaction chamber. It was found that the field emission properties from graphite-like nanostructured carbon on Si tips were greatly improved as compared with those of nanodiamond films on Si tips. A turn-on field of 1.2 V.cm^-1 was observed for high sp² content thin films on Si tips. The analysis showed that the field emission enhancement effect was caused by the tip geometry, tunnel effect and sp² content in the films. However, the geometrical enhancement was greater than that of the tunnel and sp² content effects.