Wo3/Tio2 Composite Multi-Layer Photoanode Based Dye Sensitized Solar Cells: Promoting Electron Injection Process

Dye-sensitized solar cells are promising alternative photovoltaics because of environmentally friendly features. Nanocrystalline TiO2, used as electron-transporting layer in DSSCs, plays an important role in exciton separation and charge injection process. However, its relatively low electron diffusion coefficient hampered further optimization using pure TiO2 film as photoanode electrode. Accordingly, a narrow bandgap WO3 electron transport layer along with a negative conduction band edge was introduced on the bottom of the traditional TiO2 film to promote electron injection process. DSSCs with 540 nm WO3 and TiO2 multi-layer exhibits the best short-circuit current density of 13.04 mA/cm(2) and photoelectric conversion efficiency of 5.39%, 40% higher compared to the traditional configured devices.