Tremendous achievements of colloidal quantum-dot (QD) light-emitting diodes (QLEDs) in both efficiency and lifetime have been witnessed in the past decade. However, multiple interfacial losses such as defect-induced exciton quenching and multicarrier Auger recombination can severely suppress the device performance of QLEDs. Here, we present the efficient QLEDs by adopting the new liquid-solid-solution processed magnesium-doped zinc oxide nanocrystals (ZMO-LSS) as an electron-transport layer. A magic carrier relaxation dynamics is demonstrated at the QD emitter/ZMO-LSS interface for abnormal exciton recycling and enhanced radiative recombination, which arises from the subtle intragap band coupling of surface trap states as directly clarified by the prolonged electroluminescence decays of devices. Red-emitting QLEDs on rigid glass achieve a maximum external quantum efficiency (EQE) of 22.3% with virtual droop-free over a wide range of brightness from 10,000 to 200,000 cd m⁻². By further combining a silver nanowires-based composited electrode on a plastic substrate, a substantial boost in EQE up to 24.0% is realized for flexible devices. The present results provide an in-depth study on interfacial recombination and convey a clear picture of constructing ZMO-LSS for efficient QLEDs and related optoelectronic devices.

在过去的十年中，见证了胶体量子点（QD）发光二极管（QLED）在效率和寿命方面的巨大成就。然而，多种界面损失，例如缺陷诱导的激子猝灭和多载子俄歇重组，可以严重抑制QLED的器件性能。在这里，我们通过采用新型液固溶液处理的掺杂镁的氧化锌纳米晶体（ZMO-LSS）作为电子传输层，介绍了高效的QLED。QD发射器/ ZMO-LSS界面展示了神奇的载流子弛豫动力学，可用于异常激子循环和增强的辐射重组，这是由于表面陷阱态的细微带隙内带耦合所引起的，而这种现象直接由器件的长时间电致发光衰减所阐明。⁻²。通过在塑料基板上进一步组合银纳米线基复合电极，可将柔性器件的EQE大幅提高至24.0％。目前的结果提供了对界面复合的深入研究，并为构造用于高效QLED和相关光电器件的ZMO-LSS提供了清晰的画面。