Branched TiO2 nanorod arrays owning the surface anatase/rutile junctions for dye sensitized solar cells

Branched TiO2 nanorod arrays (TiO2 BNRs) owning the surface anatase/rutile junctions on FTO substrates were synthesized and applied in dye-sensitized solar cells (DSCs) comparing with the TiO2 nanorod arrays (TiO2 NRs) owning one single crystalline phase and the TiO2 nanoparticles (TiO2 NPs) owning irregular surface morphology. The branched morphology owning the surface anatase/rutile junctions was revealed by field emission scanning and transmission electron microscopy, Raman, and X-ray diffraction. The power conversion efficiency (PCE) of DSCs fabricated using TiO2 BNRs is improved to 6.5% with both enhancement of photovoltages and photocurrent densities, better than DSCs fabricated using the corresponding TiO2 NRs and DSCs fabricated using the TiO2 NPs.