Liu Zhenyang, Hao Chaoqi, Sun Yingying, Wang Junyu, Dube Lacie, Chen Mingjun, Dang Wei, Hu Jinxiao, Li Xu, Chen Ou
Hebei Key Laboratory of Optic-Electronic Information and Materials, College of Physics Science and Technology, Hebei University, Baoding 071002, China.
Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States.
Nano Lett. 2024 May 1;24(17):5342-5350. doi: 10.1021/acs.nanolett.4c01249. Epub 2024 Apr 17.
CuInS (CIS) quantum dots (QDs) represent an important class of colloidal materials with broad application potential, owing to their low toxicity and unique optical properties. Although coating with a ZnS shell has been identified as a crucial method to enhance optical performance, the occurrence of cation exchange has historically resulted in the unintended formation of Cu-In-Zn-S alloyed QDs, causing detrimental blueshifts in both absorption and photoluminescence (PL) spectral profiles. In this study, we present a facile one-pot synthetic strategy aimed at impeding the cation exchange process and promoting ZnS shell growth on CIS core QDs. The suppression of both electron-phonon interaction and Auger recombination by the rigid ZnS shell results in CIS/ZnS core/shell QDs that exhibit a wide near-infrared (NIR) emission coverage and a remarkable PL quantum yield of 92.1%. This effect boosts the fabrication of high-performance, QD-based NIR light-emitting diodes with the best stability of such materials so far.
硫化铜铟（CIS）量子点（QDs）是一类重要的胶体材料，具有广泛的应用潜力，这归因于其低毒性和独特的光学性质。尽管用硫化锌壳层包覆已被确定为提高光学性能的关键方法，但阳离子交换的发生历来会导致意外形成铜铟锌硫合金量子点，从而在吸收光谱和光致发光（PL）光谱轮廓中产生有害的蓝移。在本研究中，我们提出了一种简便的一锅合成策略，旨在阻止阳离子交换过程并促进硫化锌壳层在CIS核量子点上的生长。刚性硫化锌壳层对电子 - 声子相互作用和俄歇复合的抑制作用导致CIS/ZnS核/壳量子点具有宽的近红外（NIR）发射覆盖范围和高达92.1%的显著光致发光量子产率。这种效应推动了高性能、基于量子点的近红外发光二极管的制造，此类材料具有迄今为止最佳的稳定性。
