The ferroelectric photovoltaic effect of BiCrO3/BiFeO3 bilayer composite films.

This work involves an investigation of the structure, ferroelectricity, optical band-gap, photovoltaic spectral response and J - V performance of BiCrO 3 /BiFeO 3 bilayer composite films prepared via the solution-gelation technique. It is shown that the enhanced ferroelectric properties are observed for BiCrO 3 /BiFeO 3 bilayer composite films by interaction resulting from the coupling between BiFeO 3 and BiCrO 3 layers. The photovoltaic spectral responses of the normalized current for BiCrO 3 /BiFeO 3 bilayer composite films presents a noteworthy red-shift towards visible region compared with the pure BiFeO 3 films and the pure BiCrO 3 films. Thus photovoltaic response is attributed to the narrow band-gap of BiCrO 3 /BiFeO 3 bilayer composite films. The short circuit current density and open circuit voltage of the BiCrO 3 /BiFeO 3 bilayer composite films under white-light illumination are much higher than the values of BiFeO 3 and BiCrO 3 films. The present work provides an available way of controlling photovoltaic response of ferroelectric films and accelerating its application in light sensors, light drivers and ferroelectric photovoltaic cells. [ABSTRACT FROM AUTHOR]