Enhancing Photovoltaic And Photosensing Performances In Bismuth Ferrite Via Polar Order Engineering

Recent emerging developments have demonstrated that bismuth ferrite is one of the promising lead-free perovskite materials used in solar energy harvesting devices and photodetectors. This work reports high short-circuit photocurrent densities of similar to 1.2 x 10(3) and similar to 0.55 x 10(3) mu A/cm(2) in a p-type gadolinium-doped BiFeO3 ceramic with n-type indium tin oxide under 405 nm irradiation and sunlight at 10(2) mW/cm(2) intensity, respectively. Polarization-enhanced photoresponsivity of similar to 5.4 x 10(-2) A/W and specific detectivity of similar to 1.5 x 10(11) Jones were achieved with response times of similar to 1 and similar to 10 ms, respectively, at the rising and decaying edges. Enhanced photovoltaic conversion via a prior electric-field poling can be attributed to the p-n junction and the field-modulated Schottky barrier in conjunction with domain nucleation, ordered polar nanoregions, and increased O 2p-Fe 3d orbital hybridization. The network of domain walls and grain boundaries serves as conduction pathways for the photogenerated charge carriers. The improved photocurrent in gadolinium-doped BiFeO3 opens up an opportunity for using bismuth ferrite materials in self-powered photodetectors.