Efficiency Enhancement of Dye-Sensitized Solar Cell Using Pt Hollow Sphere Counter Electrode

[Pt hollow spheres] electrodes and [Pt-sputtered + Pt hollow spheres] electrodes were fabricated on fluorine-doped tin oxide (FTO) glass as counter electrodes for dye-sensitized solar cells (DSCs), after sputtering platinum (Pt) on polystyrene microspheres and annealing them at 500 °C for 30 min. Electrochemical impedance measurement revealed that the charge transfer resistances of [Pt hollow spheres] electrodes and [Pt-sputtered + Pt hollow spheres] electrodes were 0.91 Ω cm2 and 0.48 Ω cm2, respectively, which were less than that of 1.28 Ω cm2 obtained from [Pt-sputtered] electrode. Furthermore, the DSCs with [Pt hollow spheres] and [Pt-sputtered + Pt hollow spheres] electrodes exhibited high energy-conversion efficiencies of 8.20(±0.10)% and 8.53(±0.08)%, respectively, which were both higher than the 7.89(±0.05)% efficiency of the DSC with [Pt-sputtered] electrodes.