Current Photovoltaic Research ISSN:2288-3274(Print) 2508-125X(Online)

Soluble polyaniline was synthesized by attaching titanium isoproxide (Ti(OPr)₄) to the amine group of the aniline. Approximately 1 to 1 molar ratio of aniline and Ti(OPr)₄ was mixed and polymerized with ammonium persulfate. The FTIR result showed clear difference between TiO₂-aniline composite (TiO₂An) and TiO₂-polyaniline composite (TiO₂PAn). Although the TiO₂An had negligible UV-visible absorption, the TiO₂PAn showed strong absorption in the UV-visible region. Photoluminescence (PL) peaks of TiO₂An were shifted toward red with the reduction of the excitation energy, which could be due to the multiple emission centers. The luminescence peak shift stopped at 501 nm. The PL spectra of TiO₂PAn exhibited three emission peaks at 2.88 eV (430 nm), 2.48 eV (501 nm) and 2.22 eV (558 nm). The new emission center (2.22 eV) was observed after polymerization. Field emission scanning electron microscope image showed crack-free composite film.