Photovoltaic response of hydrothermally derived BFO ceramics

In this study, bismuth ferrite (BiFeO₃; BFO) powder was synthesised using a low-temperature hydrothermal method. The powder was characterised using X-ray diffraction (XRD) and an ultraviolet–visible spectrophotometer. The XRD analysis showed that the post-annealed BFO at 570°C possesses a perovskite structure and exhibits a rhombohedral structure without any impurity phase. A BFO ceramic capacitor (indium tin oxide (ITO)/BFO/gold (Au)) was fabricated using gold and ITO as electrodes. The ferroelectric property of the prepared BFO ceramic was confirmed by polarization–electric field (P–E) hysteresis loop measurements. Post-annealing improves the ferroelectric properties of BFO ceramic, giving an enhanced ferroelectric–photovoltaic response towards violet laser light of wavelength 405 nm at an intensity of 160 mW/cm². The values for short-circuit current density J _sc and open-circuit voltage V _oc obtained for the BFO samples were found to be 0·1 μA and 0·29 V, respectively. The obtained results are encouraging and makes the prepared BFO sample suitable for energy harvesting applications.