Zang Shuaipu, Zhang Xuhui, Sun Yingying, Li Ning, Wang Lei, Li Lin Song
Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Centre for High-efficiency Display and Lighting Technology, School of Materials, Henan University, Kaifeng, China.
College of Science, Zhongyuan University of Technology, Zhengzhou, China.
Front Chem. 2022 Dec 13;10:1102514. doi: 10.3389/fchem.2022.1102514. eCollection 2022.
Harnessing environment-friendly and low-cost multinary Cu-In-Zn-S quantum dots (QDs) as emitters for light-emitting diodes (LEDs) has attracted great attention for display and lighting application. However, suboptimal QD structure is a huge obstacle, which results in serious non-radiative recombination and efficiency roll-off. Herein, we synthesized structure-tailored Cu-In-Zn-S/ZnS//ZnS QDs by improving the reactivity of shell growth by 2-ethylhexanoic acid (EHA) ligands. The EHA-assisted shell growth can boost an extended alloyed layer at the core-shell interface and a smoothed confinement barrier, which effectively passivate the interface defects and suppress Förster resonance energy transfer (FRET) process. These synthesized QDs display a bright photoluminescence emission (quantum yield of 83%) and a larger size of 8.4 nm. Moreover, the resulting LEDs based on the EHA-assisted QDs exhibit a maximum luminance of 8074 cd/m, and a current efficiency of 7.3 cd/A with a low efficiency roll-off. Our results highlight a remarkable ligand strategy to tailor the QD structure for high performance QD-based LEDs.
利用环境友好且低成本的多元铜铟锌硫量子点（QDs）作为发光二极管（LEDs）的发光体，在显示和照明应用方面已引起了极大关注。然而，量子点结构欠佳是一个巨大障碍，这会导致严重的非辐射复合和效率滚降。在此，我们通过用2-乙基己酸（EHA）配体提高壳层生长的反应活性，合成了结构定制的Cu-In-Zn-S/ZnS//ZnS量子点。EHA辅助的壳层生长可在核壳界面处促进形成一个扩展的合金层以及一个平滑的限制势垒，这能有效钝化界面缺陷并抑制福斯特共振能量转移（FRET）过程。这些合成的量子点呈现出明亮的光致发光发射（量子产率为83%）以及8.4纳米的较大尺寸。此外，基于EHA辅助量子点所制备的发光二极管展现出8074 cd/m的最大亮度以及7.3 cd/A的电流效率，且效率滚降较低。我们的结果突出了一种卓越的配体策略，可用于定制量子点结构以制备高性能的基于量子点的发光二极管。
