Electrical and Optical Properties of Oriented (CH)x

We have measured the optical and electrical properties of both graphoepitaxially grown and shear-flow polymerized polyacetylene filmzs. The former show a pronounced optical anisotrop;y whereas the latter do not. This result is is correlated with the orientation of the chain axes relative to the fibra axes relative to the fibre axis, which is preferentially parallel in graphoepitaxially grown films. The electrical anisotropy was found to be rather weak. Optical measurements on doped (CH)_x indicate that both the characteristic IR modes at 0.11 eV and 0.17 eV and the mid-gap absorption around 0.5 eV, which have been attributed to solitonic defects, persist up to the metallic level. This result shows that both the IR modes and the mid-gap absorption are not necessarily signatures for solitonic defects. furthermore we conclude that the impurity potential is more effective than hitherto assumed.