Galle Tom, Spittel Daniel, Weiß Nelli, Shamraienko Volodymyr, Decker Helena, Georgi Maximilian, Hübner René, Metzkow Nadia, Steinbach Christine, Schwarz Dana, Lesnyak Vladimir, Eychmüller Alexander
Physical Chemistry, TU Dresden, Zellescher Weg 19, 01069 Dresden, Germany.
Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden, Germany.
J Phys Chem Lett. 2021 Jun 3;12(21):5214-5220. doi: 10.1021/acs.jpclett.1c01362. Epub 2021 May 27.
Cation exchange emerged as a versatile tool to obtain a variety of nanocrystals not yet available via a direct synthesis. Reduced reaction times and moderate temperatures make the method compatible with anisotropic nanoplatelets (NPLs). However, the subtle thermodynamic and kinetic factors governing the exchange require careful control over the reaction parameters to prevent unwanted restructuring. Here, we capitalize on the research success of CdSe NPLs by transforming them into PbSe NPLs suitable for optoelectronic applications. In a two-phase mixture of hexane/-methylformamide, the oleate-capped CdSe NPLs simultaneously undergo a ligand exchange to NHI and a cation exchange reaction to PbSe. Their morphology and crystal structure are well-preserved as evidenced by electron microscopy and powder X-ray diffraction. We demonstrate the successful ligand exchange and associated electronic coupling of individual NPLs by fabricating a simple photodetector via spray-coating on a commercial substrate. Its optoelectronic characterization reveals a fast light response at low operational voltages.
阳离子交换成为一种通用工具，可用于获得多种尚未通过直接合成获得的纳米晶体。缩短的反应时间和适中的温度使该方法与各向异性纳米片（NPL）兼容。然而，控制交换过程的微妙热力学和动力学因素需要仔细控制反应参数，以防止不必要的结构重组。在此，我们利用CdSe NPL的研究成果，将其转化为适用于光电应用的PbSe NPL。在己烷/ -甲基甲酰胺的两相混合物中，油酸封端的CdSe NPL同时经历向NHI的配体交换和向PbSe的阳离子交换反应。电子显微镜和粉末X射线衍射证明它们的形态和晶体结构得到了很好的保留。我们通过在商业基板上进行喷涂制备了一个简单的光电探测器，证明了单个NPL成功的配体交换和相关的电子耦合。其光电特性表明在低工作电压下有快速的光响应。
