Tertiary hierarchically structured TiO2 for CdS quantum-dot-sensitized solar cells

A tertiary hierarchically structured mesoporous spherical TiO2 (with a diameter of 1190 +/- 60 nm) was synthesized by combining the sol-gel and the subsequent solvothermal treatment, and applied to CdS quantum-dot-sensitized solar cells (QDSSCs). This mesoporous spherical (MS) TiO2 offers a high surface area (76.02 m(2) g(-1)), a high internal reflectance in the visible region and a pore accessibility. A conversion efficiency of 1.9% was achieved by CdS QDSSCs composed of the MS TiO2 photoanode, which corresponds to similar to 58% improvement as compared with the values obtained from the conventional devices made with 20-nm-sized nanocrystalline TiO2 under AM 1.5 illumination of 100 mW cm(-2). Thus. the MS TiO2 can be a promising candidate for the photoanode material of QDSSCs. (C) 2011 Elsevier Ltd. All rights reserved.