High average emission sites density of electron field emission from broad area diamond-amorphous carbon thin films

Diamond-amorphous carbon films were deposited on metal Mo substrates by using microwave chemical vapor deposition technique and masked technique(the Mo substrates were pretreated by special techniques). Round area of diamond-amorphous carbon films is 0.780 +/- 0.001 cm(2) The films were characterized by x-ray diffraction Raman spectrum, optical microscopy, and scanning electron microscopy. The result of experiment indicates that diamond-amorphous carbon films with graphite particulates surface morphologies and diamond submicrosized crystalline grains located in it were obtained. Based on this, a novel electron field emission device was made. The lowest turn-on field of 1V/mu m, high average emission current density of 8.0 +/- 0.1 mA/cm(2), and high average emission sites density of (2.00 +/- 0.03)x10(3) sites/cm(2) from a broad well-proportioned emission area of 0.780 +/- 0.001 cm(2) were obtained, and the smaller the graphite particulate, the better the emission character. Field enhancement due to a 'projection on a projection' geometry could be a partial explanation of the results.