Just Add Ligands: Self-Sustained Size Focusing of Colloidal Semiconductor Nanocrystals
Just Add Ligands: Self-Sustained Size Focusing of Colloidal Semiconductor Nanocrystals
复制标题
只需添加配体：胶体半导体纳米晶体的自我维持尺寸聚焦
DOI：
10.1021/acs.chemmater.7b05165
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发表时间：
2018
影响因子：
8.6
通讯作者：
Zamkov, Mikhail
中科院分区：
文献类型：
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作者：
Razgoniaeva, Natalia;Yang, Mingrui;Garrett, Paul;Kholmicheva, Natalia;Moroz, Pavel;Eckard, Holly;Royo Romero, Luis;Porotnikov, Dmitry;Khon, Dmitriy;Zamkov, Mikhail
消化成熟（DR）代表了一个强大的策略，提高胶体纳米结构的尺寸均匀性。它依赖于较大纳米颗粒的配体介导的溶解，有利于较小的纳米颗粒，通常被认为是奥斯特瓦尔德熟化的反面。尽管它成功地应用于金属胶体的尺寸聚焦，但迄今为止，半导体纳米晶体的消化成熟很少受到关注。在这里，我们探索了这种合成利基，并证明了配体诱导的半导体纳米晶体的成熟表现出一种不寻常的反应路径。半导体中DR过程的独特之处在于热激活颗粒聚结，这导致温度高于阈值（Tth= 200-220 °C）时颗粒尺寸显着增加。在此温度以下，纳米颗粒尺寸集中于系综平均直径，就像金属胶体的情况一样。聚结的热阈值的存在为控制颗粒尺寸和尺寸分散提供了一种有利的策略。使用CdS、CdSe、CsPbBr 3和CuZnSnS 4的胶体证明了这种先进的形状控制，其中在宽的直径范围内获得单分散样品。我们期望将所展示的方法扩展到其他半导体，作为调整纳米颗粒形态的简单策略。
Digestive ripening (DR) represents a powerful strategy for improving the size homogeneity of colloidal nanostructures. It relies on the ligand-mediated dissolution of larger nanoparticles in favor of smaller ones and is often considered to be the opposite of Ostwald ripening. Despite its successful application to size-focusing of metal colloids, digestive ripening of semiconductor nanocrystals has received little attention to date. Here, we explore this synthetic niche and demonstrate that ligand-induced ripening of semiconductor nanocrystals exhibits an unusual reaction path. The unique aspect of the DR process in semiconductors lies in the thermally activated particle coalescence, which leads to a significant increase in the nanocrystal size for temperatures above the threshold value (Tth= 200–220 °C). Below this temperature, nanoparticle sizes focus to an ensemble average diameter just like in the case of metal colloids. The existence of the thermal threshold for coalescence offers an expedient strategy for controlling both the particle size and the size dispersion. Such advanced shape control was demonstrated using colloids of CdS, CdSe, CsPbBr3, and CuZnSnS4, where monodisperse samples were obtained across broad diameter ranges. We expect the demonstrated approach to be extended to other semiconductors as a simple strategy for tuning the nanoparticle morphology.