Enhancement of Dye-Sensitized Solar Cells Efficiency Using Mixed-Phase TiO Nanoparticles as Photoanode.

Dye-sensitized solar cell (DSSC) is a potential candidate to replace conventional silicon-based solar cells because of high efficiency, cheap cost, and lower energy consumption in comparison with silicon chip manufacture. In this report, mixed-phase (anatase and rutile nanoparticles) TiO photoanode was synthesized to investigate material characteristics, carriers transport, and photovoltaic performance for future DSSC application. Field-emission scanning electron microscope (SEM), X-ray diffraction (XRD), photoluminescence (PL), and UV-visible spectroscopy were used to characterize mixed TiO particles. Subsequently, various mixed-phase TiO anodes in DSSC devices were measured by electrical impedance spectra (EIS) and energy efficiency conversion. The overall energy conversion efficiency of DSSC chip was improved as a result of the increase of rutile phase of TiO (14%) in anatase matrix. Synergistic effects including TiO crystallization, reduction of defect density level in energy band, longer lifetime of photoexcited electrons, and lower resistance of electron pathway all contributed to high efficiency of light energy conversion.