Modification in Photovoltaic and Photocatalytic Properties of Bismuth Ferrites by Tailoring Band-Gap and Ferroelectric Properties

Bismuth ferrite has recently been extensively studies as potential material for photovoltaic and photocatalytic applications as it provides wide opportunity to tune band-gap by site engineering with suitable elements. Further, this doping modified the optical and ferroelectric properties of bismuth ferrite for the applications. Rare-earth (Gd) and transition-element (Mn, Co and Cr) co-doped samples of bismuth ferrite have been synthesized by the sol-gel technique at low temperature. Structural characterization using X-ray diffraction reveals a phase transformation from rhombohedral to orthorhombic with co-doping in pure BFO sample. A reduction of grain size for doped bismuth ferrites samples is observed in SEM analysis. The dielectric properties get enhanced with co-doping due to decrease in the Fe 2+ ions and oxygen vacancies. Increase in the remnant polarization was obtained in doped BFO samples and maximum P r ∼1.615μC/cm 2 for Gd doped BFO sample. Decrease in band-gap values with doping has been observed from (2.35eV-1.90eV). Power conversion efficiency has been calculated with doping of different substances which results in improved photovoltaic properties with respect to pure BFO (η% ∼0.00039 to 0.026). Also, photocatalytic studies have been done for all the samples of BFO. Enhanced values of photocatalytic efficiency (η% ∼ 90.89 to 96.08) has been observed with co-doping of rare earth and transition elements in bismuth ferrites. Thus, co-doping of rare-earth and transition-element in bismuth ferrite can improve multiferroic, ferroelectric, photovoltaic and photocatalytic properties for different applications