Optical Energy Gap and Below Gap Optical Absorption of Fullerene Films Measured by the Constant Photocurrent Method and Photothermal Deflection Spectroscopy

Abstract
The CPM spectra of fullerene films was measured to obtain the below gap absorption. The optical energy gap Eo was obtained by using the Tauc's plots. Eo did not change greatly with intercalated impurities. The absorption due to intercalated impurities was found below 1.6eV.