Bulk photovoltaic effect in BaTiO3

In melt-grown BaTiO 3 single crystals steady-state photocurrents proportional to the light intensity have been observed parallel to the crystallographic c -axis. The open-circuit photovoltage exceeds the value of the band gap. Light polarized parallel and perpendicular to the c -axis respectively produces photovoltages with opposite sign. This photovoltaic effect is restricted to the ferroelectric phase.