Abstract
Abstract Patterned arrays of diamond nano-tips were grown on the back barrier side of an anodic aluminum oxide (AAO) template by hot-filament chemical vapor deposition (HFCVD) system. Hard anodization method was chosen to fabricate the AAO template of uniform structure arrays and nano diamond particles were adhered onto the AAO template by Polyethylenimine pretreatment to increase the nucleation density of diamond. Different specifications of the templates to produce different heights and pitches of the diamond nano-tips were fabricated. The surface morphology of specimen was observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The quality and field emission properties of nano-tip diamonds were examined by Raman spectroscopy and field emission meter, respectively. The field emission properties of different heights and pitches of diamond nano-tips were discussed to confirm whether the screening effect existed or not in these kinds of diamond nano-tips structures. The tip radius of diamond nano-tips about 15 nm-27 nm, the average height about 18 nm-120 nm, and the average pitch-distance from 50 nm to 205 nm were obtained. The lowest turn-on field of 2.4 V/μm and the highest field emission current density of 2523 μA/cm2 can be obtained, respectively, for the case of the nitrogen doped diamond tips array with pitch-height ratio of 2.8. This kind of diamond nano-tips array seemed no field screening effect exist within these values of pitch-height ratio.