Optimized synthesis and photovoltaic performance of TiO2 nanoparticles for dye-sensitized solar cell

This paper presents response surface methodology (RSM) as an efficient approach for modeling and optimizing TiO₂ nanoparticles preparation via co-precipitation for dye-sensitized solar cell (DSSC) performance. Titanium (IV) bis-(acetylacetonate) di-isopropoxide (DIPBAT), isopropanol and water were used as precursor, solvent and co-solvent, respectively. Molar ratio of water, aging temperature and calcination temperature as preparation factors with main and interaction effects on particle characteristics and performances were investigated. Particle characteristics in terms of primary and secondary sizes, crystal orientation and morphology were determined by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Band gap energy and power conversion efficiency of DSSCs were used for performance studies. According to analysis of variance (ANOVA) in response surface methodology (RSM), all three independent parameters were statistically significant and the final model was accurate. The model predicted maximum power conversion efficiency (0.14%) under the optimal condition of molar ratio of DIPBAT-to-isopropanol-to-water of 1:10:500, aging temperature of 36 °C and calcination temperature of 400 °C. A second set of data was adopted to validate the model at optimal conditions and was found to be 0.14 ± 0.015%, which was very close to the predicted value. This study proves the reliability of the model in identifying the optimal condition for maximum performance.