Synthesis of hierarchical barium titanate micro flowers with superior light-harvesting characteristics for dye sensitized solar cells

Hierarchical barium titanate (BaTiO3) micro flowers have been successfully grown on the conducting glass substrates by a two-step hydrothermal process. Morphological and crystal structure analyses revealed that the tetragonal phase BaTiO3 micro flowers have formed as clusters of highly crystalline, one dimensional parallelepiped nanorods of widths ranging from 50 to 500 nm. The as-grown BaTiO3 micro flowers tested as dye sensitized solar cell (DSSC) photoanode has showed maximum power conversion efficiency (PCE) of 5.13%, which is comparable to the PCE of TiO2 nanoparticles based DSSC photoanode (5.90%) measured under one sun illumination conditions. Besides, incident photon to current conversion efficiency (IPCE) and UV-visible absorption analyses have confirmed that the superior light-harvesting capability of BaTiO3 micro flowers over TiO2 nanoparticles is observed in DSSC due to their favorable morphological features and increased visible light absorption properties along with the superior charge transport characteristics of nanorods.