Mesoporous titania beads for flexible dye-sensitized solar cells

Abstract

Mesoporous anatase TiO₂ beads of 830 ± 40 nm in diameter were employed as the working electrode in flexible dye-sensitized solar cells (DSSCs). The beads were pre-sintered at different temperatures to produce good chemical connection between the TiO₂ nanoparticles within the beads. Working electrode films were produced by isostatic pressing of the pre-sintered beads on flexible ITO/PEN substrates. The effect of different pressures and pre-sintering temperatures for the beads on the performance of the devices was investigated. The mechanical pressure improved the connection between the beads; but when too high a pressure was applied, the beads were crushed, resulting in a decrease in the electron diffusion coefficient and the light scattering effect. Higher sintering temperatures connected the TiO₂ particles within the beads better but decreased the surface area. The optimized flexible device configuration used 650 °C sintered beads as a scattering layer, achieving an efficiency of 7.43%.