Field emission from awl-shaped diamond-like carbon by using filtered cathodic arc plasma technique on anodic aluminum oxide template

Awl-shaped diamond-like carbon (DLC) was directly grown on anodic aluminum oxide (AAO) template by using filtered cathodic arc plasma (FCAP) technique at room temperature. The awls of DLC were about 250nm in the height and the diameters of the awls were 100nm at the top. The awl density was estimated to be 108 cm 2. A broad asymmetric band ranging from 1100 to 1800 cm 1 was detected by Raman spectrum. This asymmetric band was characteristic band of DLC. The sp3/(sp3+sp2) ratio of C–C bond of the awlshaped DLC was measured by X-ray photoelectron spectrum, and it was about 68.3%. Field-emission properties of the awl-shaped DLC were investigated. A low turn-on field of 2.6 V/mm at 10mA/cm2 with an emission area of 3.14mm2 was achieved, and the emission current stability was very good. The results indicated that the electrons were emitted under both the effect of enhanced field because of the geometry and the work function of the DLC sample. Based on Fowler–Nordheim plot, the values of work function for the awlshaped DLC were estimated in ranges of 0.23–1.08 from a linearity plot.