Direct correlation of surface morphology with electron emission sites for intrinsic nanocrystalline diamond films

• Published in: Diamond and related materials 2004-04, Vol.13 (4), p.1022-1025
• Main Authors: Köck, F.A.M., Garguilo, J.M., Nemanich, R.J.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electron and ion emission by liquids and solids; impact phenomena; Exact sciences and technology; Field emission; Field emission, ionization, evaporation, and desorption; Materials science; Nanocrystalline; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Physics; Plasma chemical vapor deposition
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2004.01.008

Field emission properties of nanocrystalline diamond films show low turn-on fields resulting in significant electron emission at low applied fields originating from individual sites with an emission site density of ∼10 4/cm 2. We have employed a high resolution electron emission microscope operating in field emission mode to image the spatial distribution of emission sites for intrinsic nanocrystalline diamond thin films. The location of individual emission sites has been directly correlated to the surface morphology probed by scanning electron microscopy. Surface topography measurements show fine structured features consisting of micron and submicron domains separated by grain boundaries. No preferred topographic features that would account for field emission can be detected suggesting that the electronic structure of the grains and their boundaries under a high electric field has to be considered in order to account for the observed emission characteristics.