Conversion enhancement of flexible dye-sensitized solar cells based on TiO2 nanotube arrays with TiO2 nanoparticles by electrophoretic deposition

We prepared highly ordered titanium dioxide nanotube arrays (TNAs) by anodizing Ti foils in F− containing electrolyte. The thickness and dye loading amount of TNAs were 26 μm and 1.06 × 10−7 mol cm−2, respectively. TiO2 nanoparticles (TNPs) were electrophoretically deposited on the inner wall of nanotube to produce coated nanotube arrays (TNAP). The dye loading was increased to 1.56 × 10−7 mol cm−2, and the electron transport rate improved. TNAs and TNAP were sensitized with ruthenium dye N3 to yield dye-sensitized TiO2 nanotube solar cells. The power conversion efficiency of TNA-based dye-sensitized solar cells (DSSCs) was 4.28%, whereas the efficiency of TNAP-based DSSCs increased to 6.28% when illuminated from the counter electrode. The increase of power conversion efficiency of TNAP-based DSSCs is ascribed to the increased surface area of TNAs and the faster electron transport rate.

► TiO2 nanoparticles were electrophoretically deposited on TiO2 nanotube arrays. ► The charge transport rate increased after depositing TiO2 nanoparticles. ► The dye loading amount increased 47.2% after depositing TiO2 nanoparticles. ► The efficiency of dye sensitized solar cells increased from 4.28% to 6.28%.