Chiral materials, known for their unique structural and quantum properties, have garnered significant interest, with InSeI emerging as a promising chiral topologically trivial insulator. In this study, we introduce a scalable Bridgman crystal growth technique to synthesize large, environmentally stable single crystals of InSeI, achieving centimeter-sized chiral crystals with superior quality. Notably, this work marks the first report of photoluminescence (PL) emission from exfoliated InSeI chiral chains, alongside a detailed exploration of their polarization-dependent optical and phononic properties. Our Bridgman-grown crystals exhibit excellent structural integrity, enhanced exfoliation characteristics, and increased resistance to light-induced degradation compared to those produced by traditional solid-state methods. A microscopy analysis confirms the distinct chiral structure of InSeI, and the first in situ nanometer spatial resolution electron energy loss spectroscopy measurements establish a bandgap of 2.08 eV, consistent with the cryogenic PL emission peak. Angle-resolved Raman spectroscopy, combined with calculated vibrational properties, identifies five distinct frequency regions in the Raman modes, predominantly associated with In-, In-I, In-Se-I, and Se-atomic motions, with significant intensity variations under different polarization orientations. This study not only offers a practical method for synthesizing high-quality InSeI but also provides the first comprehensive experimental insights into its unique optical and vibrational properties, significantly advancing the understanding of chiral material systems.

中文翻译：

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手性平凡绝缘体 InSeI 的结构和角度分辨光学和振动性能


以其独特的结构和量子特性而闻名的手性材料引起了人们的极大兴趣，其中 InSeI 成为一种很有前途的手性拓扑平凡绝缘体。在这项研究中，我们引入了一种可扩展的 Bridgman 晶体生长技术来合成大型、环境稳定的 InSeI 单晶，从而获得具有卓越品质的厘米级手性晶体。值得注意的是，这项工作标志着首次报道了剥离的 InSeI 手性链的光致发光 （PL） 发射，同时详细探索了它们偏振依赖性的光学和声子特性。与传统固态方法生产的晶体相比，我们的 Bridgman 生长晶体表现出优异的结构完整性、增强的剥离特性和更强的抗光诱导降解能力。显微镜分析证实了 InSeI 独特的手性结构，并且首次原位纳米空间分辨率电子能量损失光谱测量确定了 2.08 eV 的带隙，与低温 PL 发射峰一致。角度分辨拉曼光谱与计算的振动特性相结合，确定了拉曼模式中的五个不同频率区域，主要与 In、In-I、In-Se-I 和 Se 原子运动有关，在不同偏振方向下具有显着的强度变化。这项研究不仅为合成高质量的 InSeI 提供了一种实用的方法，而且首次提供了对其独特的光学和振动特性的全面实验见解，极大地促进了对手性材料系统的理解。