Phase-Field Modeling of Ultrafast Domain Manipulation via the Bulk Photovoltaic Effect in Ferroelectrics

Yi-De Liou^1,2*, Kena Zhang², Jan-Chi Yang^1,3, Ye Cao², Yi-Chun Chen^1,3

¹Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
²Department of Materials Science and Engineering, The University of Texas at Arlington, Arlington, Texas 76019, USA
³Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan 701, Taiwan

* Presenter:Yi-De Liou, email:leave710584@gmail.com

Optical control of ferroelectricity is a critical frontier in the development of advanced optoferroic devices. Recent reports highlight the indirect coupling of light with ferroelectric polarization through mechanisms such as thermal depolarization, photostriction, and magnetoelectric effect. However, the influence of light-induced space charges on domain reconfiguration remains an underexplored area. In this work, we investigate the bulk photovoltaic (BPV) effect in ferroelectric oxides, where photoexcited carrier separation occurs under above-bandgap illumination, owing to the material’s non-centrosymmetric structure. Using a phase-field model that incorporates the BPV effect, we explore the microscopic interactions between ferroelectric domains and BPV currents at ultrafast timescales. Our findings reveal that BPV current variations between neighboring domains generate opposing charges at domain walls, creating electric fields as high as 1000 kV/cm within individual domains. This internal electric field not only reorients the polarization but also facilitates domain wall movement on sub-picosecond timescales, enabling non-volatile domain evolution assisted by anisotropic biaxial strain. These insights deepen our fundamental understanding of the BPV effect in ferroelectrics and pave the way for the development of ultrafast opto-ferroelectric memory devices.

Keywords: Ferroelectric materials, Bulk photovoltaic effect, Phase-field modeling, Domain manipulation, Optical control