Synthesis and characterization of ZnO tetrapod-like nanorods without catalyst by wet thermal evaporation and applied on dye-sensitized solar cells

Dye-sensitized solar cells (DSSCs) continue to attract as one of the most important renewable energy technologies due to their simple production, environmentally friendly, and lower-cost fabrication process compared to the most common types of solar cells. Zinc oxide (ZnO) nanostructures have motivated researchers to fabricate DSSCs as photo-anodes due to their unique properties, such as different types of structures, appropriate optical properties, proper energy bandgap, and high electron transfer characteristics. This article reports the simple preparation of ZnO tetrapod-like nanorods using the wet thermal evaporation method on porous silicon substrate PS/Si and applied as a photoanode on DSSCs. ZnO nanostructures were characterized by using grazing-angle X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) measurements. A significant difference in the performance of DSSCs has been investigated by using a standard dye di-tetrabutylammonium cis-bis(isothiocyanate)bis(2,2 '-bipyridyl-4,4 '-dicarboxylato) ruthenium (II) (N719) reloaded on ZnO tetrapod-like nanorods (Jsc=3.33, Voc=0.88, FF=51%, and eta=1.51%) being more efficient than the ZnO spherical nanoparticles as a reference solar cell (Jsc=2.01, Voc=0.86, FF=49%, and eta=0.89%).