Quantum dot light-emitting diodes (QD-LEDs) are expected to be used in wide-color-gamut displays because the emission colors from QDs are highly saturated. InP-based QDs are one of the most promising candidates for low-toxicity QDs. Here, we report an efficient green QD-LED whose emitting layer was composed of InP-based QDs and an organic electron-transporting material (ETM). To investigate ETMs suitable for combining with the QDs, the device characteristics of QD-LEDs with various ETMs were compared. The external quantum efficiency (EQE) and the driving voltage were found to be markedly improved by the incorporation of suitable ETMs. We demonstrated green QD-LEDs with a high maximum EQE of 10.0% and a low turn-on voltage of 2.4 V by using 2,4,6-tris(3′-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine (TmPPPyTz) as an ETM. Furthermore, to clarify the origin of the difference in device characteristics, we investigated their hole- and electron-transporting properties. The results suggested that the hole-current leakage from the QD layer was substantially suppressed in the QD-LEDs with TmPPPyTz. Using an ETM with such hole-suppressing ability is demonstrated to be an effective approach to improving the EQEs of QD-LEDs.

中文翻译：

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使用合适的有机电子传输材料的高效绿色 InP 量子点发光二极管

量子点发光二极管 (QD-LED) 有望用于宽色域显示器，因为 QD 的发射颜色高度饱和。基于 InP 的量子点是最有希望的低毒性量子点候选者之一。在这里，我们报告了一种高效的绿色 QD-LED，其发光层由基于 InP 的 QD 和有机电子传输材料 (ETM) 组成。为了研究适合与 QD 结合的 ETM，比较了 QD-LED 与各种 ETM 的器件特性。发现通过加入合适的 ETM，外量子效率（EQE）和驱动电压显着提高。我们通过使用 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl) 展示了具有 10.0% 高最大 EQE 和 2.4 V 低开启电压的绿色 QD-LED -1,3,5-三嗪 (TmPPPyTz) 作为 ETM。此外，为了阐明器件特性差异的根源，我们研究了它们的空穴和电子传输特性。结果表明，在具有 TmPPPyTz 的 QD-LED 中，QD 层的空穴电流泄漏得到了显着抑制。使用具有这种空穴抑制能力的 ETM 被证明是提高 QD-LED EQE 的有效方法。