Nanostructural conductivity and surface-potential study of low-field-emission carbon films with conductive scanning probe microscopy
Abstract
Simultaneous surface topography and conductivity/potential measurements were carried out on low-field-emission (1 V/μm) carbon films by combining conductive atomic force microscopy and Kelvin probe force microscopy. The current image showed that highly conducting sites and nonconducting regions coexisted on a micro- and/or nanoscale. Further, in situ I-V characteristics of both regions demonstrated that the conducting sites have an Ohmic property, whereas nonconducting regions have a degenerated Schottky property. When combined with the current image, the contact potential difference image showed that the conducting sites have a highest contact potential difference of 0.5 V, which implies the existence of a graphite phase. It is revealed that the conducting channels play an important role in the low-field-emission process. It is also suggested that the combination of conductivity and surface-potential measurements is an effective method for investigating complex-phase nanostructural surfaces.
- Publication:
-
Applied Physics Letters
- Pub Date:
- November 1999
- DOI:
- 10.1063/1.125377
- Bibcode:
- 1999ApPhL..75.3527Z
- Keywords:
-
- 68.35.Bs;
- 73.40.Cg;
- 73.30.+y;
- 73.25.+i;
- 79.70.+q;
- Structure of clean surfaces;
- Contact resistance contact potential;
- Surface double layers Schottky barriers and work functions;
- Surface conductivity and carrier phenomena;
- Field emission ionization evaporation and desorption