Transport properties of hydrogen-terminated nanocrystalline diamond films


We investigated hydrogen-terminated nanocrystalline diamond films (H-NCD) by resistivity and Hall effect depending on the grain size. Measured transport quantities were related to 2D-like surface system and its condition. Resistivity strongly increased when the grain size at surface decreased while the Hall concentration is independent on the granularity. Using a 2D geometrical model, we have shown that the resistivity is controlled by the transversal resistance of the grain boundaries.

Grain boundary in H-NCD
Energy profile at the grain boundary in H-NCD. Thick solid lines represent ground 2D-like state of the holes at the surface of the grain interior. Dashed line shows a possible position of the mobility edge in the disordered boundary region (“a-C”)