Influence of dye-concentration on the light-scattering effect in dye-sensitized solar cell

Abstract

We investigate the influences of dye-concentration for scattering layer in a dye-sensitized solar cell (DSSC), which is consisted with N719 dye on a bilayer anode with 250 nm-sized TiO2 film onto 20 nm-sized TiO2 film, and compared to a monolayer anode 20 nm-sized TiO2 film. The photovoltaic conversion efficiency (eta) of DSSC with the bilayer anode including a light-scattering layer (LSL-DSSC) was enhanced markedly compared to that of the DSSC with normal transparent layer anode (NTL-DSSC). This implies that the light-scattering layer increased the light amount absorbed by dyes. The eta was improved more than 80% in low concentration of dye adsorbed on TiO2, which is caused by the penetrating light up to the scattering layer. The scattering effect is more effective in lower concentrations of dye. The photovoltaic performance of LSL-DSSC was characterized by the electrochemical and photophysical analysis comparing with the NTL-DSSC. Moreover, the charge recombination and dye regeneration dynamics for DSSC were investigated using the transient absorption spectroscopic measurements. (C) 2014 Elsevier B.V. All rights reserved.