Improved photovoltaic performance of dye-sensitized solar cell upon doping with pulsed-laser fabricated plasmonic silver nanoparticles as modified photoanodes

Abstract

The use of plasmonic nanomaterials as performance enhancers in dye-sensitized solar cells (DSSCs) has recently gained significant attention, with photonic excitation of metal nanoparticles resulting in improved light entrapment and near-field excitation. However, there are limited studies on using pulsed laser-synthesized colloidal silver nanoparticles as modified photoanodes within the DSSC architecture. In this study, colloids of silver nanoparticles (Ag NPs) with varying concentrations are produced using the advanced nanosecond pulsed laser ablation in liquid technique and subsequently implanted into the TiO₂ photoanode of the N719 DSSC, forming an Ag@TiO₂ nanostructure. The optical properties, investigated through UV-visible spectroscopy, reveal a concentration-dependent absorbance of colloidal Ag NPs based on the duration of laser exposure. Using a second harmonic wavelength of 532 nm leads to the formation of spherical and quasi-spherical nanoparticles with a size range of 20–180 nm. The photovoltaic performance of a solution-processed DSSC with the Ag@TiO₂ modified photoanode at varying concentrations of Ag NPs is studied, with an optimal concentration of 13 µg/ml and doping (wt%) of 2.0%, resulting in almost a two-fold increase in photocurrent density (J_sc) of 13.56 mA/cm², and maximum power output (P_max) of 1.125 mW, with the highest power conversion efficiency (PCE) of 4.50% when compared with standard DSSC. The DSSC characterizations, including transient photocurrent response, showed higher current density for Ag-doped photoanodes compared with bare TiO_2, and the electrochemical impedance of the modified DSSC showed the lowest transfer resistance (R_c-t) of 3.6 Ω. Finally, the developed plasmonic DSSC highlights the effect of enhanced light absorption through localized surface plasmon resonance (LSPR) and enhanced charge transfer within the absorber layer, resulting in improved solar cell performance.