The relationship between the spatially resolved field emission characteristics and the Raman spectra of a nanocrystalline diamond cold cathode

Spatially resolved electron field emission measurements from a nanocrystalline diamond film grown by plasma-enhanced chemical transport deposition have been obtained using a scanning probe apparatus with micrometer resolution. Macroscopic regions with a high emission site density, and turn-on fields below 3 V/mu m, comprised approximately 1/2 of the total sample area. The emitting and the nonemitting regions of the specimen are differentiated distinctly by Raman spectra and subtly by morphologies. Both areas are largely sp(3)-bonded, but only the nonemitting regions exhibit a sharp line at 1332 cm(-1), a well-known signature of diamond in larger crystallites. (C) 1996 American Institute of Physics.