Calculation of quantum well effect for field electron emission of nanostructured carbon

Carbon nanostructures of different composition and structure including nanocrystalline diamond films, flake-like sp/sup 2/-bonded CVD carbon films, bulk diamond/sp/sup 2/-bonded carbon nanocomposites, DLC films, nanotubes, etc., often show excellent field electron emission properties with very low threshold fields of 0.5-2 V//spl mu/m and uniformity of emission properties over a large surface area. Based on the special study of microscopic properties of the field emission centers, including work function, electrical conductivity, topography and emission intensity, a mechanism of the emission for such objects is proposed, taking into account quantum properties of nanostructured carbon forms, including reduction of the tunneling barrier due to quantum well effects for thin carbon nanolayers and insulator/graphite interfaces (Karabutov et al, J. Vac. Sci. Tech. B vol. 19, p. 965, 2001). Here, this model is developed, involving detailed calculation of the field emission current from quantum wells and carbon nanostructures.