TiO2 micro/nano-composite structured electrodes for quasi-solid-state dye-sensitized solar cells

Micro/nano-composite TiO2 porous films are prepared in a nutshell by the electro- hydrodynamic (EHD) method, and are applied to dye sensitized solar cells (DSSCs) successfully. Considering that micro/nano-composite structures based on the EHD technique are better for the filling of ionic liquid and quasi-solid-state electrolytes than liquid state electrolytes, a fill factor (ff) of 78.9% and a total photoelectric conversion efficiency (eta) of 6.4% for ionic liquid electrolyte and an ff of 75.3% and an eta of 5.3% for quasi-solid-state electrolyte are obtained. Moreover, this kind of composite hierarchical structure may be of benefit for light collection because of strong light scattering. In order to obtain optimized devices, we probe into the influence of adding an amount of polymer on the photovoltaic performance, and find that by changing the concentration of the polymer during the EHD process the specific surface area of the films changes, which leads to different photovoltaic behaviour of solar cells.