Large Bulk Photovoltaic Response by Symmetry-Breaking Structural Transformation in Ferroelectric [Ba(Zr0.2Ti0.8)O3]0.5[(Ba0.7Ca0.3)TiO3]0.5

The photovoltaic effect seen in ferroelectric oxides is gaining interest for next-generation solar cells, as these materials do not suffer from the same issues regarding carrier recombination and band gap as do the commonly employed semiconductors. The authors demonstrate a large photovoltaic response in a Pb-free mixed titanate-zirconate system by electrically tuning the material's symmetry-breaking structural transformation, and correlate the effect to the preferred structural symmetry via band-structure calculations. These results give welcome insight for engineering ferroelectric oxides for photovoltaic applications.