HREELS, IR and SFG investigation of undoped and doped adsorbed fullerenes

High-resolution electron-energy-loss spectroscopy was used to characterize the vibrational fingerprint of C-60 on Ag(111) and hydrogen-passivated Si(1 11) surfaces and to investigate the interfacial structure of a chemisorbed monolayer of C-60 on Ag(111). Complementary results from infra-red absorpti on spectroscopy and sum-frequency generation spectroscopy help to interpret thr spectra in the range of the T-1u(4)-A(g)(2) peaks. Estimation of the c harge transferred to the chemisorbed monolayer upon further doping with pot assium is deduced from the frequency shifts of vibrational modes. (C) 1999 Elsevier Science B.V. All rights reserved.