Field emission from boron-doped polycrystalline diamond film at the nanometer level within grains

Surface morphology, conductivity, and field emission properties of boron-doped polycrystalline diamond film have been studied using scanning tunneling microscopy, current imaging tunneling spectroscopy, and separation-voltage (S-V) spectroscopy focusing on the properties within a single grain. The emission properties show significant spatial variations within single grains at the nanometer level. S-V spectroscopy provided direct values of the field required for the emission from nanometer-sized structures at the surface. Strong correlation between surface conductivity and low-field emission has been found. The results suggest that the emission properties of the film on the nanometer level are determined by local hydrogen termination. (C) 2000 American Institute of Physics. [S0003-6951(00)02634-6].