Nanograss-structured counter electrode for dye-sensitized solar cells

In order to improve the electrochemical and optical performance of counter electrode for solar cells, a nanograss-structured electrode on silicon is explored as counter electrode for dye-sensitized solar cells (DSSCs). The nanograss-structured counter electrode is fabricated by dry etching of silicon and followed by metal deposition. The morphological, electrochemical and optical properties of the counter electrode are characterized by scanning electron microscopy, electrochemical impedance spectroscopy and reflection spectroscopy, respectively. Compared with traditional planar counter electrodes, the energy-conversion efficiency, fill factor and short-circuit current are increased by 15.1%, 1.5% and 12.1% by the nanograss-structured counter electrode for DSSCs, respectively. The results also show that, the nanograss-structured counter electrode can effectively enhance the light scattering, provide a larger contact area with electrolyte/Pt, and reduce the charge-transfer resistance.