Potential-pulse assisted adsorption of carminic acid dye onto TiO2 nanoparticles for faster fabrication of higher efficiency sensitized solar cells

Dye adsorption onto the TiO2 nanoparticles thin film is typically the slowest step in the preparation of dye-sensitized solar cells. Potential assisted adsorption has previously shown to significantly reduce the adsorption time from several hours to minutes. However, it also reduced the cell efficiency in most of the cases and increased it up to 13 % compared to the classical adsorption method, by applying a constant potential for 60 min. In this work, pulsed potential assisted adsorption of carminic acid dye onto TiO2 nanoparticles significantly reduced the adsorption time and increased the cell efficiency up to 33 % compared to classical adsorption, applying a pulse time of 10 ms and amplitude of 0.5/-0.4 V for 30 min. On the other hand, a single-frequency electrochemical impedance measurement method for monitoring the dye adsorption onto the nanoparticles was tested and provided similar results to the capacitance measurement method. This single-frequency value was determined with the help of relative contribution impedance plots.