Experimental studies on field emission characteristic of graphite

In the present paper, detail experimental studies on field electron emission characteristic of graphite nano-tip were reported. A precursor-free plasma enhanced chemical vapor deposition (PECVD) process was developed for graphite nano-tip arrays growth. N-type <100> Si chips were used as substrates. Scanning electron microscopy (SEM) observation results indicated that the tips were grown vertically on the substrate surface. The tip height and radius are typically /spl sim/100 nm and/spl sim/10 nm, respectively. Further transmission electron microscopy (TEM) image and electron microscopy (TEM) image and electron diffraction pattern demonstrated that the graphite nano-tip is crystalline graphite. The field emission properties of the graphite nano-tip arrays were measured in an ultra-high vacuum (10/sup -8/torr) chamber. A steel anode probe was employed for the testing. The testing results indicated that the graphite nano-tip arrays typically have relatively lower threshold field for field electron emission. Possible growth mechanisms of the graphite nano-tip and the effects of the tip morphology on the field emission properties were discussed.