Two-Photon Absorption Property of a Conjugated Polymer: Influence of Solvent and Concentration on Its Property

摘要

The Suzuki coupling reaction was utilized to prepare target conjugated polymer P1, whose main chain consists of 3,5-dicyanopyridine moieties as electron acceptors and both triphenylamino groups and fluorene moieties as donors. This polymer exhibits excellent solubility in organic solvents and high thermal stability (5% of weight loss at 398 °C). Detailed spectroscopic studies including absorption and fluorescence emission in solvents of different polarity were also conducted. The influence of the solvent and concentration on its two-photon absorption (TPA) property was studied by a two-photon-induced fluorescence (TPIF) method. It was found that the highest two-photon absorption cross section (13 260 GM at a laser wavelength of 940 nm) appeared in 1,2-dichloroethane, a solvent with a moderate polarity. Meanwhile, with the increase of its concentration in chloroform, its TPA cross section value is reduced, implying that its two-photon absorption process in its chloroform solution is not a pure intrachain process.