Influence of Mg Concentration on Structural, Optical and Electrical Properties of Epitaxial-Grown Mg-Doped C<sub>60</sub> Thin Films

The effect of magnesium doping in C 60 films grown on mica was studied. An improvement on the conductivity of the films was observed when the concentration of magnesium was increased. Structural changes were also observed from the diffraction patterns of x-ray at high magnesium concentrations. A new peak in the photoconductivity spectra was observed. This new peak was also attributed to structural changes, which would lead to some changes in the carrier transport properties. The pentagonal pinch A g (2) mode of the Raman spectra weakened and shifted to lower frequencies when the magnesium concentration increased, which indicates that the C 60 molecule cage changed.