An Effective Method for Improvement of Field Electron Emission Site Density and Uniformity of Amorphous Carbon Thin Films

Amorphous carbon films are deposited on the Mo film/ceramic substrates, which are pretreated by a laser spattering chiselling technique (2 line/mm), by using the microwave chemical vapour deposition technique. The films are characterized by x-ray diffraction, Raman spectrum, optical microscopy, and scanning electron microscopy. The experimental result indicates that the laser spattering chiselling pretreated techniques can essentially improve the field emission uniformity and the emission site density of the amorphous carbon thin film devices so that its emission site density can reach the level of actual application (undistinguishable by naked eye) from a broad well-proportioned emission area of 50mm × 50mm. This kind of device can show various digits and words clearly. The lowest turn-on field below 1V/m, the emission current density over 5.0±0.mA/cm², and the highest luminance 1.0×10³cd/m² are obtained. Meanwhile, the role of the laser spattering chiselling techniques in improving the field emission properties of the amorphous carbon film are explained.