Enhancement of Natural Dye-Sensitized Solar Cell Efficiency Through TiO2 Hombikat UV100 and TiO2 P25 Photoanode Optimization

Engineering new photoanode materials to substantially improve the efficiency of natural dye-sensitized solar cells (DSSC-Ns) is a significant challenge in the field of DSSC-Ns. This study utilizes the doctor blade technique to develop novel photoanode materials based on mixtures with different proportions of TiO2 Hombikat UV100 and TiO2 P25, two nanometric powders with different grain sizes. The fabricated films were studied by X-ray diffraction, which revealed a dominant anatase phase in the structure, as was corroborated by Raman spectroscopy. The crystallite size of the materials was determined using the Scherrer method. Using optical measurements, we estimated the bandgap energy (Eg) of the photoanodes that varied in the samples at around 3 eV. The assembled solar cells demonstrated a significant efficiency of 4.87% in the TiO2 Hombikat UV100/TiO2 P25 sample with the proportion of 50–50% (HP50) of blended photoanode. This sample device exhibited a fill factor of 50.41%, an open circuit voltage (Voc) of 0.65 V, and a current density of 14.75 mA/cm2 for an active surface area of 0.19 cm2. The HP50 sample constituted highly efficient DSSC-Ns and photoanodes with lower open-circuit voltage in the series, while HP40 developed a Voc of 0.73 V, and HP30 developed a Voc of 0.70 V.