浙江大学化学系彭笑刚教授课题组近日报道了一种尺寸与表面结构高度单分散的硒化镉（CdSe）量子点及其合成方法，相关论文发表在2020年11月13日出版的《美国化学会志》上。

在该研究中，课题组人员在非配位溶剂中合成了被六个相同的(100)面包裹的、具有闪锌矿型结构的硒化镉量子点。这些量子点高度单分散的尺寸、独特的晶面结构和单一晶型使其表现出硒化镉量子点中最窄带宽的整体光致发光（半峰全宽52 meV）。

研究人员发现，在成核阶段，可以通过降低作为唯一配体来源的羧酸镉（Cd(RCOO)₂）的浓度，选择性地形成适用于生长立方体形状量子点的小尺寸（≤3 nm）硒化镉晶种。另一方面，以可溶性的CdCl_x(RCOO)_1-x（x = 0.1~0.2）形式引入的含氯离子配体虽然会导致成核过程难以受控，但却可在从热力学上稳定镉末端的(100)晶面的同时，从动力学上加速硒离子在(100)面上沉积。

结果表明，通过配体控制成核和生长，合成在尺寸和表面结构上都高度单分散的量子点是完全可行的。

附：英文原文

Title: Monodisperse CdSe Quantum Dots Encased in Six (100) Facets via Ligand-Controlled Nucleation and Growth

Author: Liulin Lv, Jiongzhao Li, Yonghong Wang, Yufei Shu, Xiaogang Peng

Issue&Volume: November 13, 2020

Abstract: Zinc-blende CdSe quantum dots (QDs) encased in six equal (100) facets are synthesized in a noncoordinating solvent. Their monodispersed size, unique facet structure, and single crystallinity render the narrowest ensemble photoluminescence for CdSe QDs (full width at half-maximum being 52 meV). The nucleation stage can selectively form small-size CdSe QDs (≤3 nm) as seeds suited for the growth of cube-shaped QDs by reducing the concentration of cadmium carboxylates (Cd(RCOO)2) as the sole source of ligands. While resulting in poorly controlled nucleation, chloride-ion ligands introduced in the form of soluble CdClx(RCOO)1–x (x = 0.1～0.2) would thermodynamically stabilize the cadmium-terminated (100) facets yet kinetically accelerate the deposition of selenium ions onto the (100) facets. Results suggest that it is fully feasible to synthesize QDs simultaneously with monodisperse size and surface structure through ligand-controlled nucleation and growth.

DOI: 10.1021/jacs.0c06914

Source: https://pubs.acs.org/doi/10.1021/jacs.0c06914