Highly Efficient Photoinduced Electron Transfer in a Novel Tetrakis(tetraphenylporphyrinatozinc)/Perylenetetracarboxidiimide Array and Its Application to a Photovoltaic Device

摘要

A novel donor-acceptor array consisting of four 5-(p-substituted phenyl)-10,15,20-triphenylporphyrinatozinc (POR) complexes attached to the 1,6,7,12-positions of perylene-3,4:9,10-tetracarboxidiimide (PDI) was synthesized and characterized. HOMO and LUMO values of the array were aquired by cyclic voltammetry. Photophysical properties were studied by steady-state UV-vis and fluorescence spectroscopy. The results showed that this compound absorbs strongly from 300 to 700 nm, making it an ideal system to harvest polychromatic light. After selective excitation of the POR moiety or PDI moiety, an almost complete fluorescence quenching was observed, indicating that highly efficient photoinduced electron transfer occurs in this array. The predominant quenching process for PDI-POR4 array is electrontransfer yielding POR4+-PDI-. The self-assemblies of this molecular in polar and nonpolar solvents were investigated. Intermolecular pi-pi interaction in cooperation with the van der Waals interaction between POP. and PDI component leads to the formation of spherical nanoparticles and ribbon-like morphological structures in methanol and n-hexane, respectively. Photoelectrochemical studies exhibited prompt and steady photocurrent photovoltage response. Moreover, photovoltaic measurement on this array reveals efficient light energy conversion properties, such as a fill factor of 0.42. These results are of particular relevance for photovoltaic nanodevices and solar energy conversion applications.