在高性能量子点发光二极管中存在界面激子猝灭吗？

Does interfacial exciton quenching exist in high-performance quantum dot light-emitting diodes?

机构信息

Institute of Nanoscience and Applications, Southern University of Science and Technology, Shenzhen 518055, China.

Key Laboratory of Energy Conversion and Storage Technologies (Southern University of Science and Technology), Ministry of Education, Guangdong University Key Laboratory for Advanced Quantum Dot Displays and Lighting, Shenzhen 518055, China.

出版信息

Nanoscale. 2023 Feb 16;15(7):3430-3437. doi: 10.1039/d2nr07119c.

DOI:10.1039/d2nr07119c

PMID:36727441

Abstract

In quantum dot light-emitting diodes (QLEDs), even seemingly with interfacial exciton quenching between quantum dots (QDs) and the electron transport layer (ETL) limiting the device efficiency, the internal quantum efficiency of such QLEDs approaches 100%. Therefore, it is a puzzle that QLEDs exhibit high performance although they suffer from interfacial exciton quenching. In this work, we solve this puzzle by identifying the cause of the interfacial exciton quenching. By analyzing the optical characteristics of pristine and encapsulated QD-ETL films, the interfacial exciton quenching in the pristine QD-ETL film is attributed to O-induced charge transfer. We further investigate the charge transfer mechanism and its effect on the performance of QLEDs. Finally, we show the photodegradation of the pristine QD-ETL film under UV irradiation. Our work bridges interfacial exciton quenching and high performance in hybrid QLEDs and highlights the significance of encapsulation in QLEDs.

摘要

在量子点发光二极管 (QLED) 中，即使量子点 (QD) 和电子传输层 (ETL) 之间的界面激子猝灭似乎限制了器件效率，这种 QLED 的内部量子效率也接近 100%。因此，尽管 QLED 受到界面激子猝灭的影响，但它们仍能表现出高性能，这是一个谜。在这项工作中，我们通过确定界面激子猝灭的原因来解决这个难题。通过分析原始和封装的 QD-ETL 薄膜的光学特性，我们将原始 QD-ETL 薄膜中的界面激子猝灭归因于 O 诱导的电荷转移。我们进一步研究了电荷转移机制及其对 QLED 性能的影响。最后，我们展示了原始 QD-ETL 薄膜在紫外光照射下的光降解。我们的工作弥合了混合 QLED 中界面激子猝灭和高性能之间的差距，并强调了封装在 QLED 中的重要性。