Nanocrystalline lanthanum-doped bismuth ferrite as a perovskite photosensitizer: Morphological, structural, optical, photovoltaic properties, and DFT calculations

Abstract

As a photosensitizer on the TiO2 photoelectrode for solar cell applications, lanthanum-doped bismuth ferrite (Ladoped BFO) was synthesized using the sol–gel method. BFO is doped at La doping contents of 5, 10, 15, and 20 wt % in bismuth ferrite. Morphological properties, structural characteristics, and chemical composition of resulting La-doped BFO samples are investigated using transmission electron microscopy, X-ray diffraction, and X-ray fluorescence analyses, respectively. Mixed phases of Bi24− xLaxFe2O39 and Bi1− xLaxFeO3 are formed for the samples annealed at 550 ◦C, resulting in a power conversion efficiency of ~1.3 % for the 15 wt% La-doped BFO sample (x = 0.15). Annealing at 700 ◦C yields the pure phase of Bi1− xLaxFeO3, achieving the maximum power conversion efficiency of ~1.9 %. Our findings show that the pure phase of BFO and optimum La doping make a potential candidate as a novel perovskite oxide-based photosensitizer in solar cell applications.