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 nanocry stalline diamond film grown by plasma-enhanced chemical transport depo sition have been obtained using a scanning probe apparatus with microm eter resolution. Macroscopic regions with a high emission site density , and turn-on fields below 3 V/mu m, comprised approximately 1/2 of th e total sample area. The emitting and the nonemitting regions of the s pecimen are differentiated distinctly by Raman spectra and subtly by m orphologies. Both areas are largely sp(3)-bonded, but only the nonemit ting regions exhibit a sharp line at 1332 cm(-1), a well-known signatu re of diamond in larger crystallites. (C) 1996 American Institute of P hysics.