فهرست نشریات علمی دسترسی آزاد ایران

Cerium (Ce), nitrogen (N), and their co-doped TiO2 nanoparticles were produced through a cost-effective sol-gel process. Samples produced were analyzed using various analysis techniques. Structural studies revealed that pure TiO2, 3 mol% Ce-doped TiO2, and 5 mol% Ce-doped TiO2 show anatase TiO2 structure, except for 7 mol% Ce-doped TiO2 and 10 mol% Ce-doped TiO2 which have semi-crystalline nature. Energy dispersive X-ray spectroscopy (EDS) results confirmed the presence of the stoichiometric ratio Ce, Ti, and O. According to the Kubelka-Munk model, the Egap value for pure TiO2 decreases with Ce content from 3.61 eV to 3.48 eV. The photoluminescence spectroscopy (PLS) analysis was performed to investigate the electron-hole recombination in both pure TiO2 and Ce-doped TiO2. After complete examination of the physicochemical properties of the synthesized Ce-doped TiO2, photovoltaic cells were assembled to compare the effects of the optimized cerium doped, nitrogen doped, and co-doped samples. In Ce-doped solar cells, 5 mol% Ce-doped TiO2 showed the highest efficiency, with a 26% improvement over the undoped sample. Nitrogen doping also enhanced the efficiency by 22%. To explore the synergistic effect, co-doping with both cerium and nitrogen was implemented. Remarkably, the co-doped cell exhibited a 46% increase in efficiency. Typical Nyquist plot obtained for the DSSC under open-circuit voltage (VOC) condition indicated low resistance to charge recombination for 5 mol% Ce-doped TiO2 sample with Rs of 23.14 Ω, R1 of 4.61 Ω, and R2 of 13.84 Ω and the longest electron lifetime of 15.23 ms, suggesting an increasing trend in VOC and a decreasing trend in recombination rate.