Probing the electronic structure of a conjugated polymer through fifth-order electroabsorption spectroscopy

Abstract The fifth-order electroabsorption spectroscopy is performed on a spin-coated polydiacetylene film, poly[Bis- p -chlorocinnamate of 10,12-Docosadiyn-1,22-diol] (PDA-ClCin-22). The fifth-order spectrum is composed of the response of linearly allowed transitions and the response of a two-photon state. These responses are consistent with our previously proposed model. The fifth-order spectrum has better resolution than the linear and third-order spectrum, and it reveals more detailed structures.