Field emission from chemical vapor deposition diamond surface with graphitic patches

The field emission properties of a polycrystalline diamond film with hydrogenated and hydrogen free surfaces have been investigated by monitoring both the emission current-voltage curve and emission site density. A very low turn-on field of electron emission was found to be 0.5 V/mum for the hydrogenated surface and 4 V/mum for the hydrogen free surface. The emission site densities were significantly reduced from 3 x 10(3) to 2 x 10(2) cm(-2) at 5 V/mum after the surface hydrogen desorption. The low turn-on field and high emission site density on the hydrogenated surface are explained by the low work function of diamond combined with graphitic patches on the surface. (C) 2002 American Vacuum Society.