State Key Laboratory of Chemical Engineering, Department of Chemistry, East China University of Science and Technology, Shanghai 200237, China.
Inorg Chem. 2012 Mar 19;51(6):3579-87. doi: 10.1021/ic2024023. Epub 2012 Feb 24.
Unlike Mn doped quantum dots (d-dots), the emission color of Cu dopant in Cu d-dots is dependent on the nature, size, and composition of host nanocrystals (NCs). The tunable Cu dopant emission has been achieved via tuning the particle size of host NCs in previous reports. In this paper, for the first time we doped Cu impurity in Zn(x)Cd(1-x)S alloyed NCs and tuned the dopant emission in the whole visible spectrum via variation of the stoichiometric ratio of Zn/Cd precursors in the host Zn(x)Cd(1-x)S alloyed NCs. A facile noninjection and low cost approach for the synthesis of Cu:Zn(x)Cd(1-x)S d-dots was reported. The optical properties and structure of the obtained Cu:Zn(x)Cd(1-x)S d-dots have been characterized by UV-vis spectroscopy, photoluminescence (PL) spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction (XRD). The influences of various experimental variables, including Zn/Cd ratio, reaction temperature, and Cu dopant concentration, on the optical properties of Cu dopant emission have been systematically investigated. The as-prepared Cu:Zn(x)Cd(1-x)S d-dots did show PL emission but with quite low quantum yield (QY) (typically below 6%). With the deposition of ZnS shell around the Cu:Zn(x)Cd(1-x)S core NCs, the PL QY increased substantially with a maximum value of 65%. More importantly, the high PL QY can be preserved when the initial oil-soluble d-dots were transferred into aqueous media via ligand replacement by mercaptoundeconic acid. In addition, these d-dots have thermal stability up to 250 °C.
与 Mn 掺杂量子点 (d-dots) 不同，Cu 掺杂剂在 Cu d-dots 中的发射颜色取决于宿主纳米晶体 (NCs) 的性质、大小和组成。在以前的报道中，通过调整宿主 NCs 的粒径已经实现了可调谐的 Cu 掺杂剂发射。在本文中，我们首次在 Zn(x)Cd(1-x)S 合金 NCs 中掺杂 Cu 杂质，并通过在宿主 Zn(x)Cd(1-x)S 合金 NCs 中 Zn/Cd 前体的化学计量比的变化，在整个可见光范围内调谐掺杂剂发射。报道了一种简便的非注入和低成本的合成 Cu:Zn(x)Cd(1-x)S d-dots 的方法。通过紫外-可见光谱、光致发光 (PL) 光谱、透射电子显微镜 (TEM) 和 X 射线衍射 (XRD) 对获得的 Cu:Zn(x)Cd(1-x)S d-dots 的光学性质和结构进行了表征。系统研究了各种实验变量（包括 Zn/Cd 比、反应温度和 Cu 掺杂浓度）对 Cu 掺杂剂发射光学性质的影响。所制备的 Cu:Zn(x)Cd(1-x)S d-dots 确实表现出 PL 发射，但量子产率 (QY) 相当低（通常低于 6%）。随着 ZnS 壳在 Cu:Zn(x)Cd(1-x)S 核 NCs 周围的沉积，PL QY 大幅增加，最大值为 65%。更重要的是，通过巯基十一烷酸的配体取代，可将初始油溶性 d-dots 从有机溶剂转移到水相介质中，从而保持高 PL QY。此外，这些 d-dots 具有高达 250°C 的热稳定性。
