FEMTOSECOND TRANSIENT ABSORPTION-MEASUREMENTS IN POLY(ARYLENEVINYLENE)S

We compare and contrast the results of transient absorption measuremen ts on three members of the poly(arylenevinylene) family: poly(p-phenyl enevinylene), PPV; poly(2,5-dimethoxy-p-phenylene vinylene), PDMeOPV; and poly(2,5-thienylenevinylene), PTV. In PTV we observe a rapid decay of the transient signal, which we relate to the low efficiency for lu minescence. We observe a much longer-lived transient absorption in PPV , which we consider to arise from singlet and triplet polaron-excitons . The results in PDMeOPV suggest the possibility that bipolarons may a lso contribute to the transient absorption.