Titania Particle Size Effect on the Overall Performance of Dye-Sensitized Solar Cells

In this paper, we report the solar cell performance of titania (TiO2) film electrodes with various particle sizes. It was found that the TiO2 nanoparticle film with smaller particles ∼10 nm in diameter resulted in a lower overall light conversion efficiency of ∼1.4% with an open-circuit voltage of ∼730 mV, a short-circuit current density of ∼3.6 mA/cm2, and a fill factor of ∼54%. Larger particles ∼23 nm in diameter resulted in a higher efficiency ∼5.2% with an open-circuit voltage of ∼730 mV, a short-circuit current density of ∼12.2 mA/cm2, and a fill factor of ∼58%. Although it was anticipated that particles with smaller diameters would adsorb more dye because of their larger surface area, it was found that particles with larger diameters had better dye adsorption for increased electron−hole generation, resulting in higher short-circuit current density and overall light conversion efficiency. Larger particles were shown to have better dye adsorption, indicating that films consisting of larger particles had greater effective surface area for greater photon absorption and electron−hole generation.