Koskela Kristopher M, Pakhira Anindya, Strumolo Marissa J, Banerjee Sarbajit, Brutchey Richard L
Department of Chemistry, University of Southern California, Los Angeles, California 90089-3502, United States.
Department of Chemistry, Texas A&M University, College Station, Texas 77845-3012, United States.
Inorg Chem. 2025 May 26;64(20):10097-10105. doi: 10.1021/acs.inorgchem.5c00710. Epub 2025 May 13.
Solution-processed AgBiS thin films were fabricated using novel thiol-amine precursor inks to investigate the stereochemical activity of Bi 6s lone pairs and their impact on the structure. A dual-space analysis combining Bragg diffraction and hard X-ray photoelectron spectroscopy (HAXPES) revealed a rock salt-like average structure with local distortions linked to cation coloring. Density functional theory (DFT) and crystal orbital Hamilton population (COHP) analyses confirmed that local Bi-rich and Ag-rich nanodomains amplify stereochemical activity, whereas more mixed and cation-order nanodomains are less stereochemically active. This local, nanoscopic mixing of segregated and ordered domains would indeed explain an average 3̅ structure that is rock salt-like and that does not manifest the full anharmonicity and noncentrosymmetry evidenced in canonical structures with stereochemical expression. These findings provide insights into the local structural and electronic complexities governing the optoelectronic properties of AgBiS thin films.
采用新型硫醇 - 胺前驱体油墨制备了溶液法处理的AgBiS薄膜，以研究Bi 6s孤对电子的立体化学活性及其对结构的影响。结合布拉格衍射和硬X射线光电子能谱（HAXPES）的双空间分析揭示了一种类似岩盐的平均结构，其局部畸变与阳离子着色有关。密度泛函理论（DFT）和晶体轨道哈密顿布居（COHP）分析证实，局部富Bi和富Ag纳米域增强了立体化学活性，而更多混合和阳离子有序的纳米域立体化学活性较低。这种局部的、纳米尺度的分离和有序域混合确实可以解释一种类似岩盐的平均3̅结构，该结构并未表现出具有立体化学表达的典型结构中所呈现的完全非谐性和非中心对称性。这些发现为控制AgBiS薄膜光电性能的局部结构和电子复杂性提供了见解。
