The optical absorption spectra for thin films of sublimed C60 and C70 are presented. Both transmission spectroscopy and photothermal deflection spectroscopy are used to obtain the spectrum over a wide energy range (0.4 to 6.2 eV) for the same film. The optical gap varies for the different fullerenes. The value for C60 is ∼ 1.6 eV and the corresponding transition appears to be optically forbidden given the weakness of the absorption. Structure is observed on the “gap edge” which can be attributed to vibronic transitions. The gap region can be described in terms used for amorphous semiconductors, having features such as an Urbach edge, and sub-gap defect absorption. The similarity suggests that the nature of fullerene thin films may be analogous to amorphous silicon and carbon films. These films have both a molecular and an amorphous semiconductor nature.
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J.H. Weaver, R. E. Smalley, et. al., Phys. Rev. Lett., 66 p1741 (1991).
S. Larsson, A. Rosen, Chem. Phys. Lett., 137 p501 (1987).
W.B. Jackson, N.M. Amer, Applied Optics, 20 p1333 (1981); N.M. Amer in Semiconductors and Semimetals Vol. 21, Part B, p83 (Academic Press NY 1984) Willardson and Beer editors.
Andrew Skumanich and J. C. Scott, Mo. Cryst. Liq. Cryst., 183 p365 (1990).
A. Skumanich, Chem. Phys. Lett., 183 p486 (1991).
A. Skumanich, N.M. Amer, and W. Jackson, Phys. Rev. B, 31 (1985) 2263.
G.D. Cody in Semiconductors and Semimetals, Vol. 21, Part D Ed. J.I. Pankove (Academic Press, San Fransisco 1984) pp11–79; A. Skumanich, A. Frova, and N.M. Amer, Solid State Comm., 54 (1985) 597.
A. Skumanich and C.R. Moylan, Chem. Phys. Lett., 174 (1990) 139.
S. Saito and A. Oshiyama, preprint.
K. Pichler, A. Smith, et. al., Condens. Matter. 3 p9259 (1991)
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Skumanich, A. Optical Spectra of Fullerenes: C60 a new amorphous semiconductor?. MRS Online Proceedings Library 270, 299–303 (1992). https://doi.org/10.1557/PROC-270-299