Dye-sensitized solar cells based on hierarchically structured porous TiO 2 filled with nanoparticles

A new morphology of TiO2 photoanodes for N-719 dye-sensitized solar cells (DSCs) has been developed with enhanced power conversion performance. Strategies for the synthesis of hierarchically structured three-dimensionally ordered macroporous (HS-3DOM) TiO2 with controlled macropore sizes (ca. 85–155 nm) by using well-arrayed polymethyl methacrylate with different diameters as well as two kinds of photoanode films based on hierarchically structured porous TiO2 filled with nanoparticles have been demonstrated. DSCs based on a special TiO2 photoanode with a macropore size of 105 nm exhibited a current density (Jsc) of 20.6 mA cm−2 and a high photo-to-electrical energy conversion efficiency (η) of 9.7%. This high power conversion efficiency is ascribed to the special morphology of the TiO2 photoanode with high dye adsorption due to its ordered and open structures, and also its light scattering and charge collection efficiency.