Giant photovoltaic effect of ferroelectric domain walls in perovskite single crystals

Abstract

The photovoltaic (PV) effect in polar materials offers great potential for light-energy conversion that generates a voltage beyond the bandgap limit of present semiconductor-based solar cells. Ferroelectrics have received renewed attention because of the ability to deliver a high voltage in the presence of ferroelastic domain walls (DWs). In recent years, there has been considerable debate over the impact of the DWs on the PV effects, owing to lack of information on the bulk PV tensor of host ferroelectrics. In this article, we provide the first direct evidence of an unusually large PV response induced by ferroelastic DWs—termed ‘DW’-PV effect. The precise estimation of the bulk PV tensor in single crystals of barium titanate enables us to quantify the giant PV effect driven by 90° DWs. We show that the DW-PV effect arises from an effective electric field consisting of a potential step and a local PV component in the 90° DW region. This work offers a starting point for further investigation into the DW-PV effect of alternative systems and opens a reliable route for enhancing the PV properties in ferroelectrics based on the engineering of domain structures in either bulk or thin-film form.

Photovoltaic effect in multi-domain ferroelectric perovskite oxides

“…The case with 109 • DW and continuous OT gives a positive short-circuit current, which is in the same direction as net polarization in the film while the rest show negative currents. Importantly, this DW-based photovoltaic effect shows that the direction of current flow does not necessarily correlates with the direction of net polarization consistent with experimental observations [6]. Furthermore, we observe strong coupling between polarization and oxygen octahedra tilt (OT).…”

Optical, electrical, and photoelectric properties of nitrogen‐doped perovskite ferroelectric BaTiO3 ceramics

“…Barium titanite (BaTiO 3 , BT), a distinguished lead‐free perovskite ferroelectric material structure, has been widely studied as a protentional alternative for conventional lead zirconate titanate (PZT)‐based applications . Besides, the anomaly photovoltaic effect in BT have also been investigated is past few decades . However, large optical absorption coefficients as well as enhanced photocurrent are still on demand in order to make it a promising photovoltaic material .…”

Mutual Insight on Ferroelectrics and Hybrid Halide Perovskites: A Platform for Future Multifunctional Energy Conversion

“…The fact that domain walls can be electrically conducting opens new pathways for a number of applications . Recently, anomalous photovoltaic effects related to domain walls in ferroelectric materials have been reported . Interestingly, electric field control over the domain structure of a material allows the photovoltaic effect to be reversed in polarity or even to be turned off.…”