Effect of nitrogen doping on the electron field emission properties of chemical vapor deposited diamond films

Nitrogen-doped diamond films were successfully synthesized using a urea/met hanol saturated solution as a nitrogen source. Scanning electron microscopy (SEM) and Raman spectroscopy revealed that the morphology and quality of t he diamond films were not altered due to nitrogen doping. However, increasi ng the urea/methanol ratio in gas mixture markedly influences the field emi ssion properties of diamond films, which were optimized when the films were grown using H-2/CH4/urea = 300:18:6 seem . The electron field emission of the films can be turned at a low field as 5.0 V mu m(-1) and the emission c urrent density as large as J(e) = 1019 mu A cm(-2) can be attained at 21.6 V mu m(-1) applied field. The effective work function is phi(e) = 0.034 eV. (C) 2000 Published by Elsevier Science S.A. All rights reserved.