量子点的有序组装及其两相界面调控用于提高QLED稳定性的研究

Under the huge demand of display industry, quantum dot light-emitting-diodes (QLEDs) are expected to lead the development of next-generation display technology, and its application prospects have received extensive attention. However, the QLED fabricated by the solution processing method has two serious problems: 1) the aging characteristics of the organic transport material and 2) the structural defect cause the damage of the QD film under the condition of large charge injection. Both of these poses a challenge to the lifetime of QLED. Based on the previous studies, this project solves this key problem by constructing a new type QLED based on inorganic transport structure: (1) Using phase separation technology to assemble QD so that high flatness and order-packaged QD film is achieved. The formation process of the phase separation structure is explained by the dynamic angle; (2) Implementing two-phase interface control between the QD and oxide transport layers. Specifically, two ultra-thin insulating barrier layers are inserted at both sides of the QD emissive layer to built a physical isolation between the oxide defect state and the excitons in QD layer, which also contributes to the improved stability of the QLED. This project will greatly improve the technologies related to long-lifetime QLED and promote its application in the display industry.

在显示产业巨大需求的牵引下，量子点电致发光二极管（QLED）有望引领下一代显示技术的发展，其应用前景受到了广泛的关注。然而溶液加工方法制备的QLED存在有机传输材料易老化特性及器件结构缺陷引发大电荷注入条件下量子点膜层损坏问题，对QLED寿命形成了挑战。在前期的研究基础上，本项目通过构建新型的无机传输层结构QLED，解决目前QLED面临的关键问题：（1）采用相分离技术，实现量子点薄膜自组装效果，制备高平整度、有序堆积的膜层结构，并以动力学角度阐明相分离结构的形成过程；（2）实施量子点/氧化物传输层的两相界面调控，在量子点发光层两端分别插入超薄绝缘阻挡层，实现无机氧化物缺陷态与量子点发光层的物理隔离，提高器件工作稳定性。预本项将极大地完善长寿命QLED的相关技术，推动其在显示领域的应用。

溶液加工方法制备的QLED存在有机传输材料易老化特性及器件结构缺陷引发大电荷注入条件下量子点膜层损坏问题，对QLED寿命形成了挑战。本项目通过构建新型的无机传输层结构QLED，解决目前QLED面临的关键问题。本项目实施QD/氧化物传输层的两相界面调控，通过硅氧烷包覆量子点，量子点成膜后，在量子点发光层两端分别形成超薄绝缘阻挡层，实现无机氧化物缺陷态与QD发光层的物理隔离，提高器件工作稳定性。此外，本项目发展了表面处理的叠层NiO空穴传输层，两相结合可以有效改善QLED稳定性问题，推动其在显示领域的应用。