Quantum-Dot Light-Emitting Diodes for Outdoor Displays with High Stability at High Brightness
Quantum-Dot Light-Emitting Diodes for Outdoor Displays with High Stability at High Brightness
复制标题
DOI：
10.1002/adom.201901145
复制
发表时间：
2019-10-28
影响因子：
9
通讯作者：
Du, Zuliang
中科院分区：
文献类型：
--
作者：
Li, Xinyu;Lin, Qingli;Du, Zuliang
量子点发光二极管（QLED）被认为是最有潜力在显示器中应用的候选光源。 QLED 在亮度、外量子效率 (EQE) 甚至工作寿命方面的最新进展已经满足了低光水平显示器的要求。然而，高亮度下的短使用寿命限制了QLED在户外显示和照明方面的应用。这里展示的是绿色 QLED，其 T-95 工作寿命在高亮度 (1000 cd m(-2)) 下可达 2500 小时，峰值 EQE 为 23.9%，电流效率为 100.5 cd A(-1)，在高电流下效率滚降较低。 QLED 的 EQE 和寿命均优于迄今为止报道的所有溶液加工绿色 QLED。这些重大进展定性地归因于使用壳定制策略来生产具有高光致发光量子产率的成分梯度 CdZnSe/ZnSe/ZnSeS/ZnS 量子点，抑制非辐射福斯特共振能量转移和俄歇复合，以及有利的价带排列以增强空穴注入。总的来说，这项工作代表着在最终实现用于高亮度显示和照明应用的 QLED 方面向前迈出了一大步。
Quantum dot light-emitting diodes (QLEDs) are considered to be the candidate light sources with the most potential for applications in displays. Recent advances in luminance, external quantum efficiency (EQE), and even the operation lifetime of QLEDs have already satisfied the requirements for low-light-level displays. However, the short operation lifetime under high brightness limits the application of QLEDs for outdoor displays and lightings. Here, demonstrated are green QLEDs with a T-95 operation lifetime reaching up to 2500 h at high brightness (1000 cd m(-2)) with a high peak EQE of 23.9%, current efficiency of 100.5 cd A(-1), and low efficiency roll-off at high current. Both the EQE and lifetime of the QLEDs are superior to those reported to date for all solution-processed green QLEDs. These major advances are qualitatively attributed to the use of a shell-tailoring strategy for producing compositional graded CdZnSe/ZnSe/ZnSeS/ZnS quantum dots with a high photoluminescence quantum yield, suppressed nonradiative Forster resonant energy transfer and Auger recombination, and favorable valence band alignment for enhanced hole injection. Collectively, this work represents a huge step forward in eventually realizing QLEDs for high-brightness display and lighting applications.