Carbon-based materials have been of great interest due to their potential application in cold cathodes for field emission displays and other vacuum microelectronic devices. Pyrolyzed polyaniline (PPANI) with N-doped nanostructures was prepared by pyrolysis of polyaniline at high temperature of 900 degrees C. The morphologies and microstructures were investigated by scanning electron microscopy, transmission electron microscopy, AFM, Raman spectroscopy, and X-ray photoelectron spectroscopy. It was found that there were sp(2)C -N and sp(3)C -N bonds between the nitrogen and the carbon atoms in the nanostructures of the PPANI obtained. The electron field emission investigations showed that the turn-on field and effective work function phi(e) of PPANI were 1.7 V/mu m and 0.010 eV which were lower than N-doped amorphous carbon films obtained by other methods. (C) 2008 Elsevier B.V. All rights reserved.