Unraveling the Origin of Interfacial Oxidation of InP-Based Quantum Dots: Implications for Bioimaging and Optoelectronics
Unraveling the Origin of Interfacial Oxidation of InP-Based Quantum Dots: Implications for Bioimaging and Optoelectronics
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DOI：
10.1021/acsanm.0c02814
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发表时间：
2020-12-24
影响因子：
5.9
通讯作者：
Kenis, Paul J. A.
中科院分区：
文献类型：
--
作者：
Vikram, Ajit;Zahid, Arwa;Kenis, Paul J. A.
磷化铟核/壳纳米晶有望在生物成像和光电子应用中取代重金属基发光材料。壳层钝化的均匀性和界面缺陷是获得更好的光学性能的关键。傅里叶变换红外光谱(FTIR)和液态和固态核磁共振光谱的结合表明，InP基核/壳量子点的界面氧化与光致发光之间存在很强的相关性。利用自动连续壳层生长方法，实现了InP/ZnSe/ZnS量子点的高效流动合成，表现出高的量子产率和窄的发射线宽度。以顺序方式将单个前体送入反应堆通道，结合在线反应监测，可以精确控制核心颗粒的逐层壳层钝化。我们的发现表明，油胺和羧酸盐(两种最常用的胶体合成起始原料)之间的无意氨解反应在脱壳过程中引入了氧化缺陷，从而限制了它们的光学性质。
Indium phosphide core/shell nanocrystals hold promise to replace heavy-metal-based emissive materials for bioimaging and optoelectronic applications. Uniformity of the shell passivation and the interfacial defects are critical for achieving improved optical properties. A combination of Fourier-transform infrared spectroscopy (FTIR) and liquid and solid-state NMR spectroscopy revealed a strong correlation between interfacial oxidation and photoluminescence of InP-based core/shell quantum dots. Using an automated sequential shell growth approach enabled efficient flow synthesis of InP/ZnSe/ZnS quantum dots, exhibiting high-quantum yields and narrow emission line widths. Feeding individual precursors into the reactor channel in a sequential fashion combined with inline reaction monitoring enabled precise control over layer-by-layer shell passivation of the core particles. Our findings suggest that an unintentional aminolytic reaction between oleylamine and carboxylates (two most commonly used starting materials for colloidal synthesis) introduces oxidative defects during the shelling process, thus limiting their optical properties.