Efficient Natural Dye-Sensitized Solar Cells Based on Spin-Coated TiO₂ Anode Materials

TiO₂ anode materials are prepared on ITO glass by spin-coated method. Dye-sensitized solar cells are assembled with these anodes and natural dyes extracted from radix ophiopogonis by different solvents. The formation and characterization of anode materials are confirmed by field-emission scanning electron microscopy, x-ray diffraction, UV-visible absorption spectroscopy. Photovoltaic testing results show that energy conversion efficiency could reach 1.67% with fill factor of 0.51, open-circuit voltage of 457 mV, and short-circuit photocurrent density of 7.2 mA/cm². The short-circuit photocurrent density can reach 7.6 mA/cm² with efficiency of 1.33.