OPTICAL-EXCITATIONS IN THIOPHENIC BASED POLYMERIC HETEROSTRUCTURES

We present evidence for the localization effect of photogenerated carr iers in a regular block copolymer made of alternating sequences of thi ophene and phenylene rings due to the presence of energy barriers whic h confine the excitations, Photoinduced (both in the visible and in th e infrared regions) and Raman spectra have been studied in dependence of the degree of polymerization of the chains. They indicate that in a long chain copolymer photoinduced species like bipolarons are more st rongly confined.