Diamond coated Si and Mo field emitters: diamond thickness effect

Individual silicon and molybdenum field emitters were coated with synthetic high-pressure diamond particles by dielectrophoresis. A comparison of the field emission characteristics before and after coating showed significant shifts of the I-V curves depending on the thickness of the coatings. A model of emission through the diamond layer is proposed that depends primarily upon tunneling through the Schottky barrier into diamond, while assuming a negligible barrier to emission from the diamond surface into vacuum. This model yields a value of the “effective” work function in agreement with experimental measurements.