Studies of amorphous carbon using X-ray photoelectron spectroscopy, near-edge X-ray-absorption fine structure and Raman spectroscopy

We report core level and valence band X-ray photoelectron spectroscopy (XPS), carbon K and oxygen K near-edge X-ray-absorption fine structure spectroscopy (NEXAFS), and Raman spectroscopy results of plasma-deposited amorphous carbon generated from fullerene C-60. In comparison with evaporated C-60, the C 1s peak is broader and asymmetric for the amorphous carbon film and its shake-up satellites disappear. The valence band shows three fairly broad peaks. Only one prominent pi* resonance occurs in the NEXAFS spectrum. Recognizable structures appear in the sigma* region indicating the formation of new bonds. In the Raman spectrum the typical D and G bands were observed. The amorphization of C60 and post-plasma functionalization of the surface after exposure to atmosphere cause changes in the electronic structure. (C) 1999 Elsevier Science S.A. All rights reserved.