Increase of Voc using heterojunctions of BaTiO3 without sensitization

In this work, we explored the properties of Barium Titanate (BaTiO3) for application in photoanodes. Unlike other works that used heterojunction, we developed a solar cell by combining Titanium Dioxide (TiO2) and BaTiO3 without sensitization. The increase of Voc in the cell with heterojunction may be explained with TiO2 acted as a blocking layer and as a charge acceptor from BaTiO3, improving the photovoltaic response of the cells, even without dye. For comparison, we developed a Dye-Sensitized Solar Cell (DSSC) by using Barium Titanate (BaTiO3) photoanodes with dye (N-3). The compounds used in the cells has been synthesized with: the microwave-assisted hydrothermal method for BaTiO3 and the Pechini method for TiO2. We use the techniques spin coating for TiO2 layer deposition and doctor blade for BaTiO3 layer. Typical features of a tetragonal structure were revealed by Raman and XAS spectroscopy, suggesting a non-centrosymmetric Ti atom in the TiO₆ octahedron. This result may generate localized states into the band gap. UV–vis absorption and photoluminescence indicate low recombination of the electron-hole pair. That may contribute to the photovoltaic behavior if associated with heterojunctions.