Lead-free chiral antimony halides enable high-sensitivity self-powered circularly polarized light detection
image: The figure shows device structure and optical properties of the lead-free chiral antimony-based halide (R/S-MBA)4Sb2Br10, highlighting its potential for high-sensitivity self-powered circularly polarized light detection and magneto-chiroptical effects.
Credit: Guangxi University
In the field of optoelectronics, the detection of circularly polarized light (CPL) is of great significance for communication, information processing, and photoelectronic devices. Traditional CPL detection often involves lead-based materials, which raise environmental concerns due to their toxicity. Recently, a research team from Guangxi University, led by Ruosheng Zeng, has made a breakthrough by synthesizing a lead-free chiral antimony-based halide, (R/S-MBA)4Sb2Br10. This material combines strong polarity and crystallographic chirality, providing a promising alternative for high-sensitivity self-powered CPL detection.
The (R/S-MBA)4Sb2Br10 halide exhibits excellent optoelectronic properties, including a significant spontaneous polarization of 5.0 μC/cm² and an optical chirality (gCD) of 0.0018. It demonstrates high sensitivity in self-powered CPL detection with distinguishable factors (gres = 0.53/-0.51 @ 0V) and a broad spectral response ranging from 365 to 980 nm. The single crystal also shows a high second-harmonic polarization response asymmetry factor (gSHG-CD = 0.98/-0.70) and strong second-harmonic generation intensity, which is 5.4 times that of commercial KH2PO4 material.
The unique magneto-chiroptical effects observed in (R/S-MBA)4Sb2Br10 are attributed to the field-effect-induced fine-tuning of exciton energy. Under an applied magnetic field, the CD signal of this material exhibits a distinct magnetic reversal phenomenon. This discovery not only deepens the understanding of magneto-chiroptical phenomena but also marks a significant advancement in achieving high-sensitivity CPL detection within the realm of lead-free polar materials.
The research team fabricated self-powered CPL photodetectors based on (R/S-MBA)4Sb2Br10 films using physical vapor deposition (PVD) technology. The results indicate that these photodetectors possess high responsivity and stability. The CISS effect in (R/S-MBA)4Sb2Br10 was further confirmed through spin injection tests, demonstrating the feasibility of spin manipulation using chiral materials.
Ruosheng Zeng, the corresponding author of this work, stated, "Our research not only provides a new avenue for the study and application of chiral materials but also opens up possibilities for the development of high-sensitivity CPL detection devices based on lead-free polar materials." The team believes that this discovery has the potential to drive innovation in optoelectronic devices and contribute to the realization of more environmentally friendly technologies.
Other contributors include Mingjian Yuan, Jialiang Xu from the Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University.
This work was supported by the Guangxi Natural Science Foundation (grant nos. 2025GXNSFDA069038), the Special Fund for Science and Technology Development of Guangxi (AD25069078), the Guangxi Natural Science Foundation (AA23073018), the National Natural Science Foundation of China (grant nos. 22175043 and 52162021), the Open Foundation of State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures (grant nos. MMCS2023OF05), and the Innovation Project of Guangxi Graduate Education (YCBZ2024009). The calculation was supported by the high-performance computing platform of Guangxi University.
About the Authors
Prof. Ruosheng Zeng is a full professor at the School of Physical Science and Technology, Guangxi University, China. His research focuses on semiconductor luminescent materials, particularly in the preparation, mechanisms, and applications of lead-free metal halides. The team has made significant progress in designing, synthesizing, and applying these environmentally friendly materials. Based at the School of Physical Science and Technology and a State Key Laboratory, they have published over 70 papers in journals including Advanced Functional Materials and Laser & Photonics Reviews, etc. For more information, please pay attention to his research homepage https://www.x-mol.com/groups/zengruosheng/publications.
About Nano Research
Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 7,000 articles. In 2024 InCites Journal Citation Reports, its 2024 IF is 9.0 (8.7, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.