Photoabsorption cross section of C60 thin films from the visible to vacuum ultraviolet

Absolute photoabsorption cross sections of C-60 thin films are determined in the hv. range from 1.3 to 42 eV by using photon attenuation method. The spectrum shows a prominent peak of 1180 Mb at 22.1 eV with several fine structures due to single-electron excitation similarly to the case of C-60 in the gas phase. The complex refractive index and complex dielectric function are calculated up to 42 eV through the Kramers-Kronig analyses. From the present data Of C-60 thin films the cross section curve of a molecular C-60 is calculated with an assumption that the polarization effect of surrounding C-60 molecules can be expressed by the standard Clausius-Mossotti relation. The spectrum thus obtained shows an excellent agreement with that Of C-60 in the gas phase measured independently. (C) 2009 Elsevier Ltd. All rights reserved.