Preparation And Photoelectric Properties Of TiO₂/SrTiO₃ Film Photoanode

The study of performance of dye-sensitized solar cell (DSSC) is focused on the selection and modification of the photoanode material, electrolyte and the cathode materials. TiO2 is a more common photoanode material when talking about the chosen of photoanode materials. However, there are many disadvantages of TiO2 photoanode, its band gap (3.2eV) limits the application in dye-sensitized solar cell, so the conversion efficiency cannot be improved. In order to suppress the complex excessive of liquid electrolyte molecular and the electrons in the TiO2 conduction band, aiming at improving the dye-sensitized solar cell conversion efficiency finally, the photoanode was modified through a series of measures by many scholars and they achieved some scientific research. This paper was based on the coating modification of TiO2, a thin layer on SrTiO3 was prepared on the surface of nanoporous TiO2 film, which is to be researched.The FTO surface was prepared a layer of dense TiO2 film by sol-gel method, then on the surface of dense TiO2 film a nanoporous TiO2 film was prepared with screen printing method, after sintering and cooling to the room temperature, a layer of SrTiO3 was prepared on the surface of nanoporous TiO2 film with hydrothermal method, after that we study the dffect on SrTiO3 at the different hydrothermal time and temperature. The samples were tested and characterized by different methods contains X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible absorption spectroscopy (UV-Vis), transmission electron microscopy (TEM) and X-ray energy dispersive spectroscopy (EDS), the DSSC was prepared after this photoanode was immersed in the dye, which was tested by a solar simulator (SSA50) and Keithley SourceMeter (Keithley2400), electrochemical workstation on the performance of the DSSC.The experimental results show that:(1) core-shell structure of TiO2/SrTiO3 light anode was successfully prepared by hydrothermal method, XRD and EDS combination indicated the presence of SrTiO3 phase, the difference of modification between before and after was showed in the SEM photos, TEM showed that there was a thin layer of SrTiO3 substances on the surface of nanoporous TiO2. (2) The UV-vis showed that the TiO2 photoanode coated SrTiO3 appeared some red shift phenomenon, band gap is reduced, which is beneficial to the dye sensitized solar cell conversion rates.(3) The core-shell structure of TiO2/SrTiO3 photoanode prepared with hydrothermal conditions of 180°Cincubation 5h optimal performance:total highest photoelectric conversion efficiency was improved by 35.65%, monochromatic light conversion efficiency was improved by 14.06%, which was better than the DSSC prepared in hydrothermal preparation holding time at 3h and 8h. DSSC (4) The DSSC preparaed of core-shell structure of TiO2/SrTiO3 photoanode reduced the dark current as a matter of improving the current density and the photoelectric conversion efficiency.