AI 中文总结
本研究通过掠角沉积结合可控衬底旋转制备出具有生长控制晶体学扭转的PbI₂纳米结构，确立其为卤化物钙钛矿手性的新起源，可实现可调手性光学响应及高g_lum值的圆偏振发光。
AI 中文摘要
控制卤化物钙钛矿的手性为圆偏振光子学、自旋选择性电子学和量子信息技术提供了新机遇。卤化物钙钛矿的手性通常通过手性分子构建块或外部施加的光子结构实现。尽管这两种方法都能产生强手性光学响应，但许多自旋依赖功能需要材料本身内部嵌入的结构对称性破缺。本文展示手性可在晶体生长过程中直接产生：将掠角沉积与可控衬底旋转相结合，制备出具有生长控制晶体学扭转的高度织构化PbI₂纳米结构。X射线织构分析表明，衬底旋转在生长过程中逐步旋转晶体取向，同时保持c轴取向，形成具有巨大且可调手性光学响应的扭转织构，包括19°的椭圆率和接近0.6的吸收不对称因子。生长过程中预设的手性通过气相转化转移至多类卤化物钙钛矿组分，产生圆偏振发光，其g_lum值可达0.23。这些发现确立了生长控制晶体学扭转是卤化物钙钛矿中此前未被探索的手性起源。
英文摘要
The ability to control chirality in halide perovskites offers new opportunities for circularly polarized photonics, spin-selective electronics, and quantum information technologies. Chirality in halide perovskites is commonly achieved through chiral molecular building blocks or externally imposed photonic architectures. Although both approaches can generate strong chiroptical responses, many spin-dependent functionalities require structural symmetry breaking embedded within the material itself. Here we show that chirality can emerge directly during crystal growth. By combining glancing angle deposition with controlled substrate rotation, we generate highly textured PbI2 nanostructures with growth-controlled crystallographic torsion. X-ray texture analysis reveals that substrate rotation progressively rotates the crystal orientation during growth while preserving the c-axis orientation, resulting in a twisted texture with giant and tuneable chiroptical responses, including ellipticities of 19° and absorption dissymmetry factors approaching 0.6. The chirality programmed during growth is transferred through vapour-phase conversion into multiple halide perovskite compositions, resulting in circularly polarized luminescence with glum values up to 0.23. These findings establish growth-controlled crystallographic torsion as a previously unexplored origin of chirality in halide perovskites.
Comments23-page main manuscript with 3 figures, plus 16 pages of supplementary information containing 11 supporting sections with additional experimental details, data analysis, and figures
