Electron field emission from patterned nanocrystalline diamond coated a-SiO2 micrometer-tip arrays

We report the fabrication of patterned nanocrystalline diamond (NCD) submicrometer-tip arrays. This includes synthesis of silica (a-SiO2) templates by conventional vapor-liquid-solid method and conformal coating of the a-SiO2 nanowires with 5–10nm sized nanodiamond grains by microwave plasma chemical vapor deposition. Detailed structural investigations were carried out by high resolution transmission electron microscopy. Electron field emission of nanodiamond emitter arrays was observed with a threshold field of 5.5V∕μm. A high emission current density of 10mAcm−2 at 11V∕μm has been obtained. This value is comparable to those of high quality NCD films deposited on silicon substrates.