PHOTOEXCITATION IN CONJUGATED POLYMERS

Conjugated polymers such as polyacetylene form a group of model semiconductors in which the 'one-dimensional' character of the polymer strongly modifies the behavior of charges added to the chains from that usually observed in three-dimensionally bonded semiconductors. The motion of chared excitations is highly anisotropic, with strong confinement to the chain through the 'polaronic' structural relaxation of the chain. This anisotropy strongly affects charge transport and charge separation following photo-excitation. In this paper we some of the recent work in this area and we present polarization-dependent measurements of photoluminescence (PL) and photo-induced absorption (PA) on highly oriented films of polyacetylene and poly(phenylenevinylene).