苏州大学Liang-Sheng Liao课题组的一项最新研究用配体-溶剂配位促进全面势阱钝化，实现了高效量子点近红外发光二极管。2024年7月10日，国际知名学术期刊《德国应用化学》发表了这一成果。

基于钙钛矿量子点(QDs)的近红外发光二极管(NIR-LEDs)可产生约15%的外量子效率(EQE)。然而，这些高性能NIR-QLEDs由于可迁移离子在量子点表面的积累，而遭受直接载流子猝灭。这些非配位离子和载流子，如果没有结合到纳米晶体表面，就会成为激子猝灭和器件降解的中心。在这项工作中，该课题组研究人员克服了这一问题，并通过设计配体锚定策略来制造高性能NIR-QLEDs，该策略需要将强结合配体(氢碘胍，GAI)溶解在中极性溶剂中。

通过采用染料敏化器件结构(磷光指示器)，该研究团队证明了界面缺陷的消除。处理后的量子点薄膜的激子结合能为117 meV，比对照(74 meV)增加了1.5倍。因此，该课题组人员报告了NIR-QLEDs的EQE为21%，这是近红外钙钛矿QLEDs的记录。这些QLEDs的运行稳定性也比之前报道的最好的近红外QLEDs高7倍。此外，课题组研究人员证明了QDs与大面积QLEDs兼容：课题组研究人员展示了EQE接近20%的900 mm² QLEDs。

附：英文原文

Title: Ligand-solvent coordination enables comprehensive trap passivation for efficient quantum dot near-infrared light-emitting diodes

Author: Ye Wang, Zong-Shuo Liu, Feng Zhao, Wei-Zhi Liu, Wan-Shan Shen, Dong-Ying Zhou, Ya-Kun Wang, Liang-Sheng Liao

Issue&Volume: 2024-07-10

Abstract: 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 mm2 QLEDs with EQE approaching 20%.

DOI: 10.1002/anie.202407833

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202407833