Department of Chemistry and ‡Centre for Nanotechnology, Indian Institute of Technology Guwahati , Guwahati-781039, Assam, India.
Langmuir. 2015 Jan 13;31(1):551-61. doi: 10.1021/la504139m. Epub 2014 Dec 26.
Herein we report the generation and control of double channel emission from a single component system following a facile complexation reaction between a Mn(2+) doped ZnS colloidal quantum dot (Qdot) and an organic ligand (8-hydroxy quinoline; HQ). The double channel emission of the complexed quantum dot-called the quantum dot complex (QDC)-originates from two independent pathways: one from the complex (ZnQ2) formed on the surface of the Qdot and the other from the dopant Mn(2+) ions of the Qdot. Importantly, reaction of ZnQ2·2H2O with the Qdot resulted in the same QDC formation. The emission at 500 nm with an excitation maximum at 364 nm is assigned to the surface complex involving ZnQ2 and a dangling sulfide bond. On the other hand, the emission at 588 nm-with an excitation maximum at 330 nm-which is redox tunable, is ascribed to Mn(2+) dopant. The ZnQ2 complex while present in QDC has superior thermal stability in comparison to the bare complex. Interestingly, while the emission of Mn(2+) was quenched by an electron quencher (benzoquinone), that due to the surface complex remained unaffected. Further, excitation wavelength dependent tunability in chromaticity color coordinates makes the QDC a potential candidate for fabricating a light emitting device of desired color output.
在此，我们报告了一种简便的配合反应，即 Mn(2+)掺杂的 ZnS 胶体量子点（Qdot）与有机配体（8-羟基喹啉；HQ）之间的配合反应，生成并控制了单一组分体系的双通道发射。这种复合量子点的双通道发射 - 称为量子点复合物（QDC） - 源于两个独立的途径：一个来自于 Qdot 表面形成的复合物（ZnQ2），另一个来自于 Qdot 中的掺杂 Mn(2+)离子。重要的是，ZnQ2·2H2O 与 Qdot 的反应导致了相同的 QDC 形成。在 364nm 的激发最大值处，发射出 500nm 的光，这归因于涉及 ZnQ2 和悬挂硫键的表面复合物。另一方面，在 330nm 的激发最大值处，发射出 588nm 的光，其可以进行氧化还原调谐，这归因于 Mn(2+)掺杂剂。与裸复合物相比，ZnQ2 复合物在 QDC 中具有更好的热稳定性。有趣的是，虽然 Mn(2+)的发射被电子猝灭剂（苯醌）猝灭，但由于表面复合物的存在，其不受影响。此外，激发波长依赖的色度坐标可调谐性使 QDC 成为制造所需颜色输出的发光器件的潜在候选者。
