Three-dimensional carbon nanowall field emission arrays

This letter reports on the fabrication of regular arrays of three dimensional graphitic structures, by growing carbon nanowalls on forests of conical Si microspikes. The high field enhancement achieved by this hierarchical growth process indicates a potential for electron emission applications. Experiments show that the field emission performance and long-term stability of the structures is by far superior to that of planar carbon nanowall mats and comparable to that reported for optimized carbon nanotube based emitters. The improved field emission properties of the fabricated arrays are attributed to the dual micro and nanomorphology of the emitters, involving a two-scale enhancement process.