The effects of donor acceptor end groups of heterocyclic molecules on two-photon absorption properties

A series of new heterocyclic molecules with different donor acceptor end groups, which possess different strength of charge transfer dipole moment, are studied by ultrafast laser spectroscopy in this work. The experimental results show that π-conjugated plane of these molecules mainly determine their fluorescent quantum efficiencies and spectra, while their strength of charge transfer dipole moment, which mainly dependent on the donor acceptor end groups, play the key role on the two-photon absorption cross-section. This results implies that design of the donor acceptor end group is important for developing molecule with large two-photon absorption cross-section in short wavelength.