Enhanced Photoelectric Properties in Dye-Sensitized Solar Cells Using TiO₂ Pyramid Arrays

In this study, the improved device performance obtained by introducing pyramid-structured photoanodes has been investigated. The periodical pyramid arrays in the TiO₂ active layer are fabricated by soft imprint lithography. The pyramid-structured photoanodes are characterized by scanning electron microscope, UV-vis spectroscopy, and electrochemical impedance spectroscopy. The experimental results demonstrate that pyramid-structured photoanodes can reduce the transmission light loss over a broad wavelength region and result in increased light reflection and scattering effect. Hence, dye-sensitized solar cells with periodical pyramid arrays can increase the light absorption in the active layer and enhance the photovoltaic performance. The overall efficiency of such structured devices is increased by 20% in comparison with the device without periodical pyramid arrays and scattering layers. Fabrication of periodical pyramid arrays of mesoporous inorganic oxide films also can be applied for other various devices with micro-/nanostructures at low cost using readily available pastes and soft imprint lithography.