@article{Deng2026, 
author = {Qihang Deng and Zhi Yang and Yunlong Bai and Lingyu Wan and Bingsuo Zou and Ruosheng Zeng},
title = {Free-bromine-induced anomalous bulk photovoltaic effect in chiral metal halides for self‑driven circularly polarized light detection},
year = {2026},
journal = {Nano Research},
keywords = {spontaneous polarization, bulk photovoltaic effect, chiral metal halides, circularly polarized light (CPL) detection},
url = {https://www.sciopen.com/article/10.26599/NR.2026.94908958},
doi = {10.26599/NR.2026.94908958},
abstract = {Chiral polar metal halides can generate spontaneous polarization, endowing them with potential for self-driven circularly polarized light (CPL) detection. However, most chiral metal halides crystallize in non-polar space groups and cannot generate spontaneous polarization, making efficient self-driven CPL detection difficult. In this work, for the first time, we propose a strategy to induce spontaneous polarization into non-polar chiral halides by introducing free halogens into the halide lattice via a solvothermal method. We find that this strategy not only breaks the intrinsic symmetry of non-polar R/S-MPZPbBr4 and transforms it into R/S-MPZPbBr4·0.5Br2 with the polar space group C2, but also induces larger octahedral distortion, which enhances the circular dichroism anisotropy factor (gCD) by 8 times. Benefiting from spontaneous polarization and the enhanced gCD, R/S-MPZPbBr4·0.5Br2 exhibits an anomalous photovoltaic effect of 3.8 V under zero bias and enables efficient self‑driven CPL detection, with an anisotropic response factor (gres) as high as 0.61. Our work opens a new pathway for designing chiral metal halides for self‑driven CPL detection.}
}