Nanocrystalline diamond films for enhanced field electron emission: graphitization or nitrogen doping?

In this paper, nitrogen-doped nanocrystalline diamond films are grown by d.c. arc plasma CVD on Si substrates. Different content in the gas mixtures and different substrate temperature are used to grow the films with different nitrogen content and microstructure. The film surface and microstructure are studied using AFM, SEM, Raman spectroscopy, X-ray photoelectron spectroscopy, Auger electron spectroscopy, and EELS to find correlations between the field electron emission and other film properties. Results show that nitrogenated nanocrystalline CVD diamond films show different microstructure than the films without nitrogen, and the field electron emission for the nitrogenated films is typically better than for the films grown without nitrogen.