TiO ₂ –BaTiO ₃ nanocomposite for electron capture in dye‐sensitized solar cells

Abstract

Abstract Different compositions of TiO 2 –BaTiO 3 nanocomposites are synthesized with various weight ratios for dye‐sensitized solar cell ( DSSC ) applications. TiO 2 and BaTiO 3 nanoparticles ( NP s) are synthesized by sol‐gel and solvothermal methods, respectively and are employed as the photoanode electrodes. BaTiO 3 NP s have pure cubic perovskite crystal structure with an average size of 20‐40 nm, while TiO 2 NP s show pure anatase phase with 15‐30 nm size. The power conversion efficiency ( PCE ) enhancement of the cells is first attained by controlling the thickness of the films for light harvesting improvement. The fabricated DSSC composed of pure BaTiO 3 NP s with an optimal thickness of 25 μm shows efficiency of 6.83%, whereas that made of pure TiO 2 NP s with 14 μm thickness has cell efficiency of 7.24%. Further improvement of cell efficiency is achieved by preparation of binary oxide nanocomposites using TiO 2 and BaTiO 3 NP s with various weight ratios. The highest PCE of 9.40% is obtained for the nanocomposite with TiO 2 :BaTiO 3 =85:15 (wt%). The enhancement is assigned to less recombination of photo‐generated electrons and higher incident photon to current conversion yield as a result of rapid charge collection and higher dye sensitization.