Electron Recombination Study of TiO۲ Compact Layers for Solid-States Solar Cells

چکیده مقاله

The role of the compact TiO2 under-layer is to form a blocking interface between the naked transparent conductive oxide coated glass areas and the hole-transport material. As these two materials make an ohmic contact, it is critical to have a compact TiO2 sub-nanometer blocking under-layer that can block the recombination of the electrons in the transparent conductive oxide coated glass with the holes in the hole-transport material. The recombination current over the transparent conductive oxide coated glass is comparatively small in a liquid-type dye-sensitized solar cells but it becomes crucial in the solid state dye-sensitized solar cells. Thus, the blocking layer in this type of solar cell has a very important role in the open-circuit potential and the efficiency of the solar cell. The blocking under-layer of TiO2 nanoparticles was deposited using spin-coating and spray methods. The layers were annealed at 450oC for 30 min. According to the SEM images, annealing at 450oC causes that the TiO2 nanoparticles aggregates on the transparent conductive oxide coated glasses. The full coverage the transparent conductive oxide coated glasses was analyzed using cyclic voltammetry that shows the decrease of the pinhole area decreases the electron recombination.