The Field Emission Characteristics of Titanium-Doped Nano-Diamonds

An electrophoresis solution, prepared in a specific ratio of titanium (Ti)-doped nano-diamond, is dispersed by ultrasound and the nano-diamond coating is then deposited on a polished Ti substrate by electrophoresis. After high-temperature vacuum annealing, the appearance of the surface and the microstructures of the coating are observed by a metallomicroscope, scanning electron microscopy and Raman spectroscopy. The field emission characteristics and luminescence features are also tested, and the mechanism of the field emission characteristics of the Ti-doped nano-diamond is analyzed. The experimental results show that under the same conditions, the diamond-coated surface (by deposition) is more uniform after doping with 5 mg of Ti powder. Compared with the undoped nano-diamond cathode, the turn-on fields decline from 6.95 to 5.95 V/µm. When the electric field strength is 13.80 V/µm, the field emission current density increases to 130.00 µA/cm². Under the applied fields, the emission current is stable and the luminescence is at its best, while the field emission characteristics of the 10 mg Ti-doped coating become worse, as does the luminescence. The reason for this could be that an excessive amount of TiC is generated on the surface of the coating.