Fullerene thin films of about 200 nm thicknesses have been deposited by thermal evaporation method on soda lime glass at substrate temperature 303 and 403 ºK under pressure about 10 -5 mbar. This study concentrated on the effect of substrate temperature on optical properties of C60 thin films within the visible range. Optical characterization has been carried out at room temperature using the absorption spectra, at normal incidence, in range 200-900 nm.
The absorption and extinction coefficients of the samples have been evaluated according to the variation in the UV- Vis spectrum. Increasing substrate temperature causes decreasing in optical band gap energy, for direct allowed transitions, and slightly changing in refractive index. This incident was attributed to the reducing of interatomic spacing, which may be associated a decrease in the amplitude of atomic oscillations around their equilibrium positions.