Photovoltaic creation of charged domain walls in barium titanate

The optical control of domain structures in ferroelectrics is of great interest. In the present work, we demonstrate the reliable creation of charged domain walls - conductive channels in otherwise insulating barium titanate - by a combined effect of light and electric field. We propose a scenario for the documented process, in which the bulk photovoltaic effect plays the key role, providing charge screening at the walls. Our scenario is supported by the results of phase-field simulations. The results are of interest for future reconfigurable electronic and opto-electronic devices.