Assembly of CdSe Quantum Dots onto TiO2 Flower-rod Films for Quantum Dot-sensitized Solar Cell Applications

Abstract

A hierarchical double-layered TiO2 flower-rod structure composed of three-dimensional (3D) TiO2 flowers and one-dimensional (1D) nanorods on transparent fluorine-doped tin oxide (FTO) conducting glass has been synthesized by a facile hydrothermal method and was applied as photoanode in CdSe quantum dots sensitized solar cells (QDSSCs). The 3D TiO2 flowers with the increased surface areas can adsorb more QDs, which reinforce the absorption of light; meanwhile 1D TiO2 nanorods beneath the flowers offer a direct electrical pathway for photogenerated electrons, accelerating the electron transfer rate. The effect of coating cycles of QDs on the photovoltaic performance was investigated by successive ionic layer adsorption reaction (SILAR) cycles. The best power conversion efficiency of solar cell based on flower-rod structure with 12 SILAR cycles of CdSe QDs can reached to 1.98% under one sun illumination (AM 1.5G, 100 mW/cm2).