Ultrasonic-Assisted Synthesis of Poly(3-hexylthiophene)/TiO 2 Nanocomposite and Its Photovoltaic Characteristics

The nanocomposites of poly(3-hexylthiophene) (PAT6) encapsulating titanium oxide (TiO 2 ) with different TiO 2 weight fractions were synthesized by in situ ultrasonic-assisted polymerization, and investigated in terms of their optical properties, microstructures and photoconductivity. The interaction between PAT6 and TiO 2 and the nature of chain growth were investigated and explained according to the results of Fourier transform infrared spectroscopy (FTIR). The increase in conjugation length of the polymer and the improvement of crystallinity with an increase in TiO 2 weight fraction were investigated and explained according to the results of UV–vis absorption spectroscopy, photoluminescence spectroscopy and X-ray diffractometry (XRD). Particle dimensions were measured and the nature of association between the components was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The photoconductivity of the PAT6/TiO 2 composite increased markedly and was discussed by taking the photoinduced charge transfer between PAT6 and TiO 2 into consideration.