A nanostructure-based counter electrode for dye-sensitized solar cells by assembly of silver nanoparticles

A nanostructure-based Pt counter electrode for dye-sensitized solar cells (DSSCs) is fabricated by assembly of silver nanoparticles on glass substrate and deposition of a thin Pt layer. This typical counter electrode has several unique behaviors such as good conductivity, quasi-uniform undulating morphology and high surface area. Studies indicate that the application of the FTO-free nanostructure-based Pt counter electrode in DSSCs can decrease the charge-transfer resistance of the Pt/electrolyte interface, enlarge the light pathway and enhance the light reabsorption superior to the devices with planar Pt counter electrode. In addition, theoretical analysis and experimental study demonstrate that the hot electrons injection effect caused by Localized Surface Plasmon Resonance effect of silver nanoparticles enhances the charge transport characteristic at the Pt/electrolyte interface, and this SPR effect makes the certain contributions on the enhancement of the photovoltaic performance of DSSCs. Compared to the DSSC with traditional planar counter electrode, the incident photon-to-current conversion efficiency, short-circuit current, and power conversion efficiency of DSSCs with nanoparticulate structure are increased by 1.117 times, 1.156 times, and 1.145 times, respectively; and the final power conversion efficiency (PCE) increases from 6.95% to 7.96%. (C) 2014 Elsevier B.V. All rights reserved.