Although the performance of quantum dot light‐emitting diodes (QLEDs) has been greatly improved in recent years, the multilayer device structure has become increasingly complex, limiting the practical application of QLEDs. Here, a novel trilayer PIN QLED with only three functional layers, which are Spiro‐OMeTAD:TFB bulk‐heterojunction (BHJ) hole transport layer (HTL), quantum‐dot emitting layer and ZnMgO electron transport layer is demonstrated. Due to the enhanced hole injection capability and suppressed electron leakage of Spiro‐OMeTAD:TFB BHJ HTL, the trilayer PIN QLED can show an excellent external quantum efficiency (EQE) of 25.1% and an impressive brightness of 299300 cd m−2 at only 8 V, which are significantly higher than those of conventional QLED. Moreover, the device stability is also remarkably improved due to the mitigation of hole accumulation and removal of unstable PEDOT:PSS. By using liquid alloy EGaIn as cathode, a fully solution‐processed vacuum‐free trilayer PIN QLED with a higher EQE of 27.3% can be further realized. The developed trilayer PIN QLEDs, with better performance and fewer functional layers, can promote the commercialization of QLED technology.

中文翻译：

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高效、稳定的量子点发光二极管，采用三层 PIN 架构


尽管近年来量子点发光二极管 （QLED） 的性能得到了很大提高，但多层器件结构变得越来越复杂，限制了 QLED 的实际应用。在这里，展示了一种新型的三层 PIN QLED，只有三个功能层，即 Spiro-OMeTAD：TFB 体异质结 （BHJ） 空穴传输层 （HTL）、量子点发射层和 ZnMgO 电子传输层。由于 Spiro-OMeTAD：TFB BHJ HTL 增强的空穴注入能力和抑制的电子泄漏，三层 PIN QLED 在仅 8 V 时即可表现出 25.1% 的出色外部量子效率 （EQE） 和 299300 cd m-2 的令人印象深刻的亮度，明显高于传统 QLED。此外，由于减少了空穴积累和去除了不稳定的 PEDOT：PSS，器件稳定性也得到了显著提高。通过使用液态合金 EGaIn 作为阴极，可以进一步实现 EQE 高达 27.3% 的完全固溶处理的无真空三层 PIN QLED。开发的三层 PIN QLED 具有更好的性能和更少的功能层数，可以促进 QLED 技术的商业化。