We propose a device model that elucidates the role of domain walls in the photovoltaic effect in multi-domain ferroelectric perovskites. The model accounts for the intricate interplay between ferroelectric polarization, space charges, photo-generation and electronic transport. When applied to bismuth ferrite, results show a significant electric potential step across both 71-degree and 109-degree domain walls, which in turn contributes to the photovoltaic (PV) effect. We also find a strong correlation between polarization and oxygen octahedra tilts, which indicates the nontrivial role of the latter in the PV effect. The domain wall-based PV effect is further shown to be additive in nature, allowing for the possibility of generating above-bandgap voltage
@article{arxiv.1811.07948,
title = {Photovoltaic effect in multi-domain ferroelectric perovskite oxides},
author = {Ying Shi Teh and Kaushik Bhattacharya},
journal= {arXiv preprint arXiv:1811.07948},
year = {2019}
}