The photoelectric nanocomposites of poly(2-methoxy-5-octyloxy)-p-phenylene vinylene/Tb₄O₇ (PMOCOPV/Tb₄O₇) were prepared by dehydrochlorination in situ polymerization. The result of Fourier transform infrared spectroscopy indicates that PMOCOPV is coated on the surface of Tb₄O₇. The absorption of PMOCOPV/Tb₄O₇ is strengthened with the contents of Tb₄O₇ increasing, and a red shift of the absorption peak can be clearly observed in the UV-Vis spectrum. Photoluminescence spectroscopy indicates that the maximum emission wavelength of the PMOCOPV/Tb₄O₇ is blue-shifted and intensity of photoluminescence increases with increasing Tb₄O₇ concentration. PMOCOPV/Tb₄O₇ shows fluorescence increasing, which involved the inter-molecular photo-induced charge transfer process. The optical band gap of PMOCOPV/Tb₄O₇ decreases gradually with the contents of Tb₄O₇ increasing. Third-order optical nonlinear susceptibility of PMOCOPV/Tb₄O₇ nanocomposites was measured by degenerate four wave mixing. The results show that the third-order nonlinear optical responses of PMOCOPV/Tb₄O₇ nanocomposites are enhanced gradually when Tb₄O₇ content increased, which can be attributed to inter-molecular photo-induced electron transfer and delocalized π electron coupling between PMOCOPV and Tb₄O₇.

Key words: poly(2-methoxy-5-octyloxy)-p-phenylene vinylene, Tb₄O₇, nanocomposite, photophysical property, fluorescence lifetime