High color purity blue quantum dot light-emitting diodes (QLEDs) have great potential applications in the field of ultra-high-definition display. However, the realization of eco-friendly pure-blue QLEDs with a narrow emission linewidth for high color purity remains a significant challenge. Herein, a strategy for fabricating high color purity and efficient pure-blue QLEDs based on ZnSeTe/ZnSe/ZnS quantum dots (QDs) is presented. It is found that by finely controlling the internal ZnSe shell thickness of the QDs, the emission linewidth can be narrowed by reducing the exciton-longitudinal optical phonon coupling and trap states in the QDs. Additionally, the regulation of the QD shell thickness can suppress the Förster energy transfer between QDs in the QLED emission layer, which will help to reduce the emission linewidth of the device. As a result, the fabricated pure-blue (452 nm) ZnSeTe QLED with ultra-narrow electroluminescence linewidth (22 nm) exhibit high color purity with the Commission Internationale de l'Eclairage chromatic coordinates of (0.148, 0.042) and considerable external quantum efficiency (18%). This work provides a demonstration of the preparation of pure-blue eco-friendly QLEDs with both high color purity and efficiency, and it is believed that it will accelerate the application process of eco-friendly QLEDs in ultra-high-definition displays.

中文翻译：

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通过壳工程减少纯蓝色 ZnSeTe 量子点的发射线宽以实现高颜色纯度发光二极管

高色纯度蓝色量子点发光二极管（QLED）在超高清显示领域具有巨大的应用潜力。然而，实现具有窄发射线宽和高色纯度的环保纯蓝色 QLED 仍然是一个重大挑战。本文提出了一种基于 ZnSeTe/ZnSe/ZnS 量子点 (QD) 制造高色纯度和高效纯蓝色 QLED 的策略。研究发现，通过精细控制量子点内部ZnSe壳厚度，可以通过减少量子点中的激子-纵向光学声子耦合和陷阱态来缩小发射线宽。此外，调节QD壳厚度可以抑制QLED发射层中QD之间的Förster能量转移，这将有助于减小器件的发射线宽。结果，所制造的具有超窄电致发光线宽（22 nm）的纯蓝色（452 nm）ZnSeTe QLED 表现出高色纯度，国际照明委员会色坐标为（0.148，0.042）和相当大的外量子效率(18%)。该工作为同时具有高色纯度和效率的纯蓝色环保QLED的制备提供了示范，相信将加速环保QLED在超高清显示中的应用进程。