Investigation of the properties of ball-milled ZnO nanostructured photoanodes for DSSC applications

Zinc oxide nanoparticles have attracted considerable attention in dye-sensitized solar cells applications because of its structural and tunable optical properties. But, improving morphological, particle size, and surface area for improved light harvesting and electron transfer remains challenging. This work explores the synthesis of ZnO using the solvothermal route at various reaction temperatures and the subsequent impact of ball milling on its material properties. The impact of temperature and ball milling is extensively investigated through micro-strain, dislocation density, and crystallite structure, using X-ray diffraction and Raman study. The ball-milled ZnO samples demonstrated a substantial improvement in short-circuit current density (J_sc), increasing approximately four times from ~ 1.54 mA cm⁻² in the as-prepared sample to 4.7 mA cm⁻². Among all samples, Z160 BM shows the highest device performance, delivering an open‑circuit voltage (V_oc) of 520 mV, J_sc of 4.7 mA cm⁻², a fill factor of 36%, and efficiency (η) of 0.86%. The impact of optimized ZnO shows better solar cell efficiency via DSSC application. The outcomes demonstrates the strategies to optimize ZnO synthesis for advanced photovoltaic applications.