STRUCTURAL AND ELECTRONIC STUDIES OF C-60 FILMS DEPOSITED USING IONIZED CLUSTER BEAM DEPOSITION

Films of a new form of carbon allotrope, C60, also known as fullerenes, are deposited on Si(111) substrates by the ionized cluster beam deposition technique under an accelerating field less than 100 V. Raman spectra and x-ray photoelectron spectroscopy measurements are carried out to analyse the electronic properties of the films, to indicate the existence of C60 soccer-balls in the films. The resistance of this C60 film deposited here to oxygen contamination is better than that deposited by molecular beam epitaxy. Binding energies of C Is peaks for C60 and highly oriented pyrolytic graphite are 284.7 and 284.3 eV, respectively. X-ray theta-2theta diffraction investigations show that C60 films deposited under V(a) = 0 V have highly textured close-packed structure with x-ray diffraction assignment (110), while those deposited under V(a) = 65 V turn out to be more polycrystalline. C60 soccer-balls are found to be broken into fragments as accelerating field exceeds about 400 V, indicated by the results of x-ray photoelectron spectroscopy, Raman spectra, x-ray diffraction, and ultraviolet visible absorption spectra.