Photophysical characterization, two-photon absorption and optical power limiting of two fluorenylperylene diimides

Perylene diimides have unique optical and electronic properties and have attracted interest in fields ranging from nonlinear optics to photovoltaics. The steady-state linear photophysical properties, two-photon absorption (2PA) spectra, and optical limiting behavior of fluorenylperylene diimide-based derivatives were investigated in solution at room temperature. An efficient intramolecular energy transfer and specific strong dependences of fluorescence quantum yield on solvent properties were observed. The 2PA spectra were measured over a broad spectral region by two-photon induced fluorescence and open aperture Z-scan methods under femtosecond and picosecond excitation, respectively. The maximum values of pure 2PA cross sections, up to similar to 3500 GM, were obtained for fluorenylperylene diimide-based derivatives under picosecond excitation, when excitedstate absorption and stimulated emission processes were taken into account. These perylene derivatives exhibited efficient two-photon optical power limiting under picosecond excitation.