• Panetta, Riccardo
• Quaranta, Simone
• Pascasio, Francesco Di
• Latini, Alessandro
• Cavallo, Carmen
• Salleo, Alberto
• Gozzi, Daniele

Abstract

<jats:title>Abstract</jats:title><jats:p>Solid solutions of the rare earth (RE) cations Pr<jats:sup>3+</jats:sup>, Nd<jats:sup>3+</jats:sup>, Sm<jats:sup>3+</jats:sup>, Gd<jats:sup>3+</jats:sup>, Er<jats:sup>3+</jats:sup> and Yb<jats:sup>3+</jats:sup> in anatase TiO<jats:sub>2</jats:sub> have been synthesized as mesoporous beads in the concentration range 0.1–0.3% of metal atoms. The solid solutions were have been characterized by XRD, SEM, diffuse reflectance UV-Vis spectroscopy, BET and BJH surface analysis. All the solid solutions possess high specific surface areas, up to more than 100 m<jats:sup>2</jats:sup>/g. The amount of adsorbed dye in each photoanode has been determined spectrophotometrically. All the samples were tested as photoanodes in dye-sensitized solar cells (DSSCs) using N719 as dye and a nonvolatile, benzonitrile based electrolyte. All the cells were have been tested by conversion efficiency (<jats:italic>J</jats:italic>–<jats:italic>V</jats:italic>), quantum efficiency (IPCE), electrochemical impedance spectroscopy (EIS) and dark current measurements. While lighter RE cations (Pr<jats:sup>3+</jats:sup>, Nd<jats:sup>3+</jats:sup>) limit the performance of DSSCs compared to pure anatase mesoporous beads, cations from Sm<jats:sup>3+</jats:sup> onwards enhance the performance of the devices. A maximum conversion efficiency of 8.7% for Er<jats:sup>3+</jats:sup> at a concentration of 0.2% has been achieved. This is a remarkable efficiency value for a DSSC employing N719 dye without co-adsorbents and a nonvolatile electrolyte. For each RE cation the maximum performances are obtained for a concentration of 0.2% metal atoms.</jats:p>

Topics

• surface
• scanning electron microscopy
• x-ray diffraction
• electrochemical-induced impedance spectroscopy
• Ultraviolet–visible spectroscopy