Photoexcitations in disubstituted polyacetylene: solitons and polarons

摘要

We studied the photoexcitations in films of disubstituted polyacetylene, a #pi#-conjugated polymer with degenerate ground state. We found that the polymer in its pristine form supports charged and neutral topological soliton excitations. Photo-oxidized films or polymer/C_(60) blends show, in addition, polaron excitations. At the same time the polymers show a strong emission band with high quantum efficiency, which leads to stimulated emission in thin films and lasing in cylindrical #mu#-cavities. These excitation properties are unique among polymers of both degenerate and non-degenerate ground state.