Wang Ye, Liu Zong-Shuo, Zhao Feng, Liu Wei-Zhi, Shen Wan-Shan, Zhou Dong-Ying, Wang Ya-Kun, Liao Liang-Sheng
Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for, Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, 215123, Jiangsu, China.
Macao Institute of Materials Science and Engineering, Macau University of Science and Technology, Taipa, 999078, Macau, China.
Angew Chem Int Ed Engl. 2024 Oct 1;63(40):e202407833. doi: 10.1002/anie.202407833. Epub 2024 Sep 2.
Near-infrared light-emitting diodes (NIR LEDs) based on perovskite quantum dots (QDs) have produced external quantum efficiency (EQE) of ~15 %. However, these high-performance NIR-QLEDs suffer from immediate carrier quenching because of the accumulation of migratable ions at the surface of the QDs. These uncoordinated ions and carriers-if not bound to the nanocrystal surface-serve as centers for exciton quenching and device degradation. In this work, we overcome this issue and fabricate high-performance NIR QLEDs by devising a ligand anchoring strategy, which entails dissolving the strong-binding ligand (Guanidine Hydroiodide, GAI) in the mediate-polar solvent. By employing the dye-sensitized device structure (phosphorescent indicator), we demonstrate the elimination of the interface defects. The treated QDs films exhibit an exciton binding energy of 117 meV: this represents a 1.5-fold increase compared to that of the control (74 meV). We report, as a result, the NIR QLEDs with an EQE of 21 % which is a record among NIR perovskite QLEDs. These QLEDs also exhibit a 7-fold higher operational stability than that of the best previously reported NIR QLEDs. Furthermore, we demonstrate that the QDs are compatible with large-area QLEDs: we showcase 900 mm QLEDs with EQE approaching 20 %.
基于钙钛矿量子点(QDs)的近红外发光二极管(NIR LEDs)的外量子效率(EQE)已达到约15%。然而,这些高性能的近红外量子发光二极管(NIR-QLEDs)由于可迁移离子在量子点表面的积累而遭受即时载流子猝灭。这些未配位的离子和载流子(如果不与纳米晶体表面结合)会成为激子猝灭和器件退化的中心。在这项工作中,我们通过设计一种配体锚定策略克服了这个问题,并制造出了高性能的近红外量子发光二极管,该策略包括将强结合配体(碘化胍,GAI)溶解在中极性溶剂中。通过采用染料敏化器件结构(磷光指示剂),我们证明了界面缺陷的消除。经处理的量子点薄膜表现出117meV的激子结合能:这比对照样品(74meV)增加了1.5倍。结果,我们报道了外量子效率为21%的近红外量子发光二极管,这在近红外钙钛矿量子发光二极管中是一个记录。这些量子发光二极管的工作稳定性也比之前报道的最佳近红外量子发光二极管高出7倍。此外,我们证明了量子点与大面积量子发光二极管兼容:我们展示了外量子效率接近20%的900mm量子发光二极管。