The effects of gold colloid concentration on photoanode electrodes to enhance plasmonic dye-sensitized solar cells performance

Pulsed laser ablation of gold (Au) bulk immersed in ethanol and post-ablated size modification process were employed to generate homogeneous size distribution of nanoparticles (~15 nm) and different concentrations of Au colloids without using chemical reagents in the final preparation. A specific concentration of N719 dye molecules with or without Au colloidal solution at different concentrations was mixed and embedded onto the porous titanium dioxide films for photoanodes formation in dye-sensitized solar cells (DSSCs). Optical measurements confirmed the interaction between the dipole moments of the dye and the localized surface plasmon resonance (LSPR) of Au nanoparticles (AuNPs), thereby indicating that AuNPs were in close contact with the adsorbed dye molecules on the surface of the photoanode. The LSPR effects of AuNPs on the performance of DSSCs have been extensively studied by using different concentrations of Au colloids. It was found that, the performance of DSSCs is highly dependent on the concentration of AuNPs. For the highest concentration (9 × 10¹² particles/mL), the best achieved plasmonic DSSC performance exhibited a power conversion efficiency of 5.36 %, whereas the reference DSSC (without AuNPs) showed an efficiency of 3.82 %. Thus, an enhancement factor of 40.31 % is indicated.