Nonlinear Optical Properties of D-π-A-π-D Type Oligomers with Different Conjugation Length
- Received Date: 2015-04-11
Abstract: The conjugation length-dependent nonlinear optical properties of fluorenone-based linear conjugated oligomers have been investigated by experimental and theoretical methods. In-frared spectra and the steady-state absorption spectra show that the increase of conjugated unit could enhance the stretching vibration peaks of C=C and lead to a red-shift of the absorption peaks. Meanwhile, the two-photon fluorescence (TPF) intensity is gradually en-hanced with the increase of excitation energy, and the TPF effciency is obviously higher after the introduction of fluorene-ethylene units. The sum-over-states approach was used to model the two-photon absorption (TPA) cross-sections of oligomers, and the theoretical values agree well with the experimental data obtained from the femtosecond open-aperture z-scan technique. The results exhibit that the extension of conjugated system indeed plays a role in the improvement of TPA behavior of oligomers.
|Citation:||Tian-hao Huang, Ying-hui Wang, Tian-ning Xu, Feng-ying Yu, Han-zhuang Zhang, Yu-ran Wang. Nonlinear Optical Properties of D-π-A-π-D Type Oligomers with Different Conjugation Length[J]. Chinese Journal of Chemical Physics , 2015, 28(5): 557-562. doi: 10.1063/1674-0068/28/cjcp1504065|