High-sensitivity self-powered circularly polarized light detection based on chiral antimony-based halides with strong polarity
Zhi Yang, Yunlong Bai, Jiandong Yao, Jie Wu, Sheng Cao, Yangding Qiu, Bingsuo Zou, Mingjian Yuan, Jialiang Xu, Lingyu Wan, Ruosheng Zeng
Abstract
Chiral organic-inorganic hybrid halides show significant potential for applications in circularly polarized photodetection, chiral-induced spin selectivity effects (CISS), and nonlinear optics. However, the widespread use of toxic lead element poses environmental concerns, hindering the further applications. Herein, we synthesized a zero-dimensional (0D) lead-free chiral antimony-based halide (<em>R</em>/<em>S</em>-MBA)<sub>4</sub>Sb<sub>2</sub>Br<sub>10</sub> with the coexistence of polarity and crystallographic chirality. The halides exhibit unique magneto-chiroptical effects due to the field-effect-induced fine-tuning of exciton energy, which is the first observation<strong> </strong>in chiral antimony-based halides. Furthermore, owing to its significant spontaneous polarization (5.0 μC/cm<sup>2</sup>) and optical chirality (g<sub>CD</sub> = 0.0018), (<em>R</em>/<em>S</em>-MBA)<sub>4</sub>Sb<sub>2</sub>Br<sub>10</sub> halide exhibits excellent performance in self-powered circularly polarized photodetection, nonlinear optics, and CISS effects. The self-powered photodetector demonstrates high sensitivity with distinguishable factors (g<sub>res</sub> = 0.53/-0.51 @ 0V) and broad spectral response. The single crystal (<em>R</em>/<em>S</em>-MBA)<sub>4</sub>Sb<sub>2</sub>Br<sub>10</sub> also exhibits a high second-harmonic polarization response asymmetry factor (g<sub>SHG-CD</sub> = 0.98/-0.70) and strong second-harmonic generation intensity. These performances are among the best reported for chiral halides. Our research not only sheds new light on the investigation of magneto-chiroptical phenomena, but also marks a significant advancement in realizing high-sensitivity circularly polarized light detection within the realm of lead-free polar materials.