Enhancing the Performance of Dye-Sensitized Solar Cells with a Gold-Nanoflowers Box.

To improve the electron collection, electron lifetime, and light-harvesting efficiency of dye-sensitized solar cells simultaneously, Au nanoflowers were prepared and used to cover the entire TiO2 film. Deposition of Au nanoflowers around the TiO2 film formed a light-scattering "box" that covered the entire TiO2 film. Compared with a light-scattering layer that only covers the top surface of TiO2 , the Au-nanoflowers box exhibited better light-harvesting efficiency due to omnidirectional light scattering, faster electron transport (attributed to the formation of electron channels between the metallic Au nanoflowers and the electron-collection electrode), and slower charge recombination. As a consequence, the short-circuit photocurrent and open-circuit photovoltage were both enhanced significantly, which improved the power conversion efficiency from 8.12 to 10.91 % (34 %) when an Au-nanoflowers box was wrapped around the photoanode.