Synthesis and application in solar cell of poly(3-octylthiophene)/titania nanotubes composite

Amorphous titania nanotubes with diameters between 20 and 30 nm were successfully synthesized by hydrothermal method using anatase TiO₂ as the precursor and 10 M NaOH as the mine to the agent. A conducting polymer composite, poly(3-octylthiophene)/titania nanotubes (P3OT/TiO₂NTs) was synthesized by situ-chemical method. Transmission electron microscope (TEM) and scanning electron microscope (SEM) depicted the morphology of the samples, defining that TiO₂NTs were successfully coated by poly(3-octylthiophene) molecules. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (IR) showed the chemical interaction of poly(3-octylthiophene) and titania nanotubes in the composite. Cyclic voltammetry (CV) curves showed that the forbidden band gap of the P3OT/TiO₂NTs composite is 0.672 eV, realizing the complementary advantages of n and p semiconductor. Ultraviolet-visible spectra (UV-vis) and fluorescence spectra (PL) showed that its optical performance is far superior to poly(3-octylthiophene) and titania nanotubes separately. Solar cell was sensitized by P3OT/TiO₂NTs. A solar-to-electric energy conversion efficiency of 0.593% was attained with the system.