Abstract

Investigations of the ultrafast relaxation dynamics of quasi one-dimensional π-conjugated polymers with non-degenerate ground states, such as polydiacetylenes and polythiophenes, have found characteristic ultrafast spectral shifts and decay kinetics of the photoinduced absorbance changes, which can be interpreted with a model of self-trapped exciton (STE) relaxation process proposed by Kobayashi and coworkers^[1−3]. The STE relaxation model characterizes the spontaneous relaxation of the free exciton to the STE state, which then decays, primarily via tunneling, through a barrier between the STE and the adiabatic ground state potential energy surface. In this study, the applicability of this model to the ultrafast photoexcitation relaxation dynamics of the π-conju- gated polymer, poly(2,5-thienylene vinylene) (PTV), a type of poly(arylene vinylene) with the chemical structure of -(X-CH=CH)-_n, where X is a thienylene group, is examined.

© 1992 IQEC