Characterization of electron emission from planar amorphous carbon thin films using in situ scanning electron microscopy

Electron emission characteristics combined with in situ scanning electron microscope images have been measured on a series of amorphous carbon films grown by pulsed laser deposition. Uniform, reproducible current–voltage characteristics without morphological damage are only observed with sequential voltage ramps ⩽5 V/s for anode-cathode gaps of 10–200 μm. The field threshold and emission barrier increase with laser energy density used during film growth. This dependence of emission parameters on film growth conditions appears to be correlated with the presence of conducting filaments extending through the film thickness.