Engineering of D205 Dye Concentration and Incorporation of Plasmonic Silver Nanoparticles in ZnO Nanorods for Enhanced Solar Energy Conversion

ABSTRACT Dye concentration engineering and the incorporation of plasmonic silver nanoparticles (AgNPs) improved the performance of dye‐sensitized solar cells (DSSCs) based on ZnO nanorods (ZnONRs). ZnONRs were synthesized using a low‐temperature hydrothermal method and sensitized with the organic dye D205 at concentrations ranging from 0.4 to 1.6 mM. Structural analysis revealed the formation of highly crystalline hexagonal wurtzite ZnONRs with an average crystallite size of 57 nm and rod diameter of 587 nm. Photovoltaic measurements revealed that a 1 mM concentration of D205 resulted in the highest power conversion efficiency (PCE) of 1.48%, as well as a reduced optical bandgap of 2.08 eV. The incorporation of 15 wt.% AgNPs at the optimized dye concentration increased the PCE to 1.57% while decreasing the bandgap to 2.07 eV, owing to improved light harvesting via localized surface plasmon resonance. The synergistic effect of optimized dye loading and plasmonic enhancement demonstrates an effective strategy for improving charge generation and photovoltaic performance in DSSCs based on ZnONRs.