Long-range dipole-dipole energy transfer enhancement via addition of SiO2/TiO2 nanocomposite in PFO/MEH-PPV hybrid thin films

Different weight ratios of poly(9,9-dioctylfluorene-2,7-diyl) (PFO)/poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) hybrid thin films, with and without a SiO2/TiO2 nanocomposite (NC), were successfully prepared using a solution blending method. All samples were deposited onto glass substrates by a spin coating technique to produce homogeneous thin films. The effect of the SiO2/TiO2 NC on the enhancement of the energy transfer mechanism in the PFO/MEH-PPV hybrids was investigated. The energy transfer parameters were calculated on the basis of the absorption and emission measurements. The long-range dipole-dipole energy transfer (Forster type) between the acceptor and donor molecules was enhanced in the presence of the SiO2/TiO2 NC in the hybrid thin films. The addition of the SiO2/TiO2 NC in the PFO/MEH-PPV hybrids reduced the distance between the donor and acceptor molecules more than the individual addition of SiO2 or TiO2 nanoparticles. Moreover, the direct relationships between the acceptor contents and energy transfer parameters, such as the energy transfer radius (R-DA), energy transfer efficiency (eta), and energy transfer probability (P-DA), were estimated using theoretical fittings. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47845.