Improved Performance of Solid-State Dye-Sensitized Solar Cells with CuI: Structure Control of Porous TiO2 Films

By increasing the pore and particle size of porous TiO2 films, the photovoltaic properties of solid-state dye-sensitized solar cells were dramatically improved. We analyzed the relation between the photovoltaic property and the microstructure of TiO2/Dye/CuI measured by scanning electron microscopy of the cross section of the cells. The larger pore size of the TiO2 films improved the CuI filling and the high degree of filling improved the short-circuit current density. Multilayered TiO2 films consisting of a TiO2 layer with small TiO2 particles and a second layer with larger TiO2 particles gave a power conversion efficiency under 1 sun of 6.0%. (C) 2012 The Japan Society of Applied Physics