Wen Je-Ruei, Rodríguez Ortiz Freddy Alberto, Champ Anna, Sheldon Matthew T
Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States.
Department of Materials Science & Engineering, Texas A&M University, College Station, Texas 77843-3255, United States.
ACS Nano. 2022 May 24;16(5):8318-8328. doi: 10.1021/acsnano.2c02474. Epub 2022 May 11.
The fast kinetics of all-inorganic CsPbX (X = Cl, Br, or I) nanocrystal growth entail that many synthetic strategies for structural control established in other semiconductor systems do not apply. Rather, products are often determined by thermodynamic factors, limiting the range of synthetic outcomes and functionality. In this study, we show how reaction kinetics are significantly slowed if nanocrystals are prepared using a dual injection strategy that moderates the crucial interaction between cesium and halide during nucleation and growth. The result is highly uniform nanorod or cuboid nanocrystals with a controllable size and aspect ratio across the quantum confinement regime, obtainable for both pure and mixed halide compositions. Further, the crystal lattice is continuously tunable between the tetragonal (4/) and orthorhombic () phases, independent of the overall nanorod morphology, enabling significantly more sophisticated structure-property relationships that can be tailored during this kinetically controlled synthesis.
全无机CsPbX（X = Cl、Br或I）纳米晶体生长的快速动力学意味着许多在其他半导体系统中建立的用于结构控制的合成策略并不适用。相反，产物往往由热力学因素决定，这限制了合成结果和功能的范围。在本研究中，我们展示了如果使用双注入策略制备纳米晶体，反应动力学将如何显著减慢，该策略可在成核和生长过程中缓和铯与卤化物之间的关键相互作用。结果是在整个量子限制范围内获得尺寸和纵横比可控的高度均匀的纳米棒或长方体纳米晶体，纯卤化物和混合卤化物组成均可实现。此外，晶格可在四方相（4/）和正交相（）之间连续调节，与整体纳米棒形态无关，从而能够建立在这种动力学控制合成过程中可定制的更为复杂的结构 - 性能关系。
