Enhanced photoconversion efficiency in dye-sensitized solar cells through Ag and La modified ZnO photoanodes

This work synthesized ZnO nanoparticles doped and co-doped with Ag and La using a cost-efficient sol-gel method. The structural and morphological features of the nanoparticles were characterized by x-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The XRD and FE-SEM confirm the formation of the hexagonal structure of all the synthesized samples. Optical properties were analyzed using UV-visible absorption and photoluminescence spectroscopy. These nanoparticles were subsequently employed as photoanodes in dye-sensitized solar cells (DSSCs). Several configurations of Ag and La doped and co-doped ZnO nanoparticles were tested as photoanodes to assess their impact on device performance. The introduction of Ag and La dopants into ZnO leads to a notable enhancement in the photovoltaic efficiency of the DSSCs. The DSSC incorporating bare ZnO photoanode achieved an efficiency of 0.2554% and on the other hand Ag and La co-doped ZnO photoanode achieved the highest efficiency of 0.9483%, a 271% increase compared to DSSC using undoped ZnO photoanodes. This significant improvement is attributed to the combined effects of Ag and La ions. Ag ions help create a blocking layer that suppresses electron recombination, while La ions enhance light absorption by broadening the spectrum through up/down conversion. The combined effect of Ag and La dopants is responsible for the observed efficiency enhancement in the DSSCs.