Preparation And Characterization Of Film. C60

In this thesis we have expatiated on the methods of the C60 thin films preparation, and the process with vacuum evaporation. The effect, which was caused by different gas pressures and other element doped, on surface morphology, structure and optical properties of C60 films have been studied by using scanning electron microscopy(SEM), ultraviolet visible optical absorption spectroscopy (UV/ VIS)(type: UV-240), ellipsometer and X-ray diffraction.The SEM shows: The C60 thin films, which were prepared in vacuum condition, consist of spherical cluster and have an average diameter about of 20~50nm. While in gas condition, the average diameter from 50nm to 200nm, and the average diameter of particles increases with the increase of gas pressure.The UV/VIS shows: The UV/VIS spectra of the films grown in gas pressure markedly differed from that of the C60 films grown in vacuum, a continuous red shifting of all feature peaks occurs in gas C60 cluster film distinctly; also the ranges of the red shifting increases little with the increase of gas pressure. The bandgap energy of Ar gas C60 thin film is 2.24 eV, and the bandgap energy of N2 gas film is 2.09 eV. Both are larger than that of vacuum C60 thin films (2.02 eV).The measure of ellipsometer shows: The refractive index value of C60 cluster films in gas atmosphere is smaller than that of vacuum C60 films (our measurement result is 1.94) and refractive index value of C60 cluster films in Ar is larger than that in N2. Both refractive index values are nearly the same in lower pressure (about 1.46), but decrease with increasing gas pressure.XRD reveals a mixture structure of the face-centered cubic and hexagonal close-packed phases.The Sn doped makes the electrical conductivity change from insulator to n-type semiconductor.