Influence of nondiamond carbon etching on field emission property of highly sp² bonded nanocrystalline diamond films

The influence of the nondiamond carbon etching on the electron field emission behavior of highly sp² bonded nanocrystalline diamond films has been systematically investigated by performing hydrogen treatment. Field emission property and emission pattern of the films are initially enhanced and then degraded with the hydrogen treatment. The most uniform distribution of emission site is obtained for one-minute hydrogen-treated film. The reason for this is explained in terms of the increase of triple junction sites due to etching of the sp² bonded carbon (nondiamond carbon) by atomic hydrogen. On the other hand, the degraded emission property of the films treated over 10 min is due to the decrease of triple junction, which is indirectly confirmed by Raman and Auger electron spectroscopies.