Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1287113 | Journal of Power Sources | 2014 | 7 Pages |
•The sugar apple-shaped TiO2 hierarchical spheres were prepared by a facile hydrothermal method.•The TiO2 hierarchical spheres had a prominent light scattering effect.•DSSCs based on TiO2 double-layer film had the maximum conversion efficiency.
The sugar apple-shaped TiO2 hierarchical spheres are prepared by a facile hydrothermal method using polyethylene glycol 600 as stabilized reagent, (NH4)2TiF6 and urea as starting materials at 180 °C. The characterizations show that the TiO2 hierarchical sphere has well-defined pyramid-shaped crystal facets. The as-prepared TiO2 hierarchical spheres are crystalline of the anatase phase, with a diameter of about 2–4 μm and a surface area of 36.846 m2 g−1. The optical investigation evidences that the sugar apple-shaped TiO2 hierarchical sphere film exhibits a prominent light scattering effect at a wavelength range of 600–800 nm due to the unique hierarchical morphology. Furthermore, the sugar apple-shaped TiO2 hierarchical spheres are deposited as the scattering layer to balance the dye adsorption and light scattering effect in DSSCs and a 7.20% solar energy conversion efficiency is demonstrated, indicating an improvement compared with the P25 cell (6.68%). Based on the optical and electrochemical investigations, the high conversion efficiency is mainly due to the effective suppression of the back reaction of the injected electron with the I3− in the electrolyte and excellent light scattering ability.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide