通过减少界面处的电荷积累来提高绿色磷光有机发光二极管的工作寿命。

Increasing the operating lifetime of green phosphorescent organic light emitting diodes by reducing charge accumulation at the interface.

作者信息

Wu Yibing, Luo Jianhui, Lin Chengwei, Zhu Tengfei, Qiao Xianfeng, Yang Dezhi, Dai Yanfeng, Sun Qian, Chen Jiangshan, Ma Dongge

机构信息

Institute of Polymer Optoelectronic Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, People's Republic of China.

Hangzhuo Institute of Quality and Technical Supervision and Inspection, Hangzhou 310000, People's Republic of China.

出版信息

Phys Chem Chem Phys. 2023 Feb 8;25(6):4598-4603. doi: 10.1039/d2cp05797b.

DOI:10.1039/d2cp05797b

PMID:36723048

Abstract

The stability and degradation mechanism of phosphorescent organic light emitting diodes (OLEDs) has been an unresolved problem in the past decades. Here, we found that electron accumulation at the interface between the electron blocking layer and the emitting layer is one of the reasons for device degradation. By inserting a thin layer with a shallower LUMO level than that of the electron transporting layer between the emitting layer and the electron transporting layer, we successfully reduced the density of electrons at the interface and greatly improved the lifetime of the resulting green phosphorescent OLEDs. The half decay lifetime LT at the initial luminance of 1000 cd m reached as high as 399 h, which is 1.7 times longer than that of the compared device without a thin layer.

摘要

在过去几十年中，磷光有机发光二极管（OLED）的稳定性和降解机制一直是一个未解决的问题。在此，我们发现电子在电子阻挡层与发光层之间的界面处积累是器件降解的原因之一。通过在发光层和电子传输层之间插入一层LUMO能级比电子传输层浅的薄层，我们成功降低了界面处的电子密度，并显著提高了所得绿色磷光OLED的寿命。在初始亮度为1000 cd m时，半衰寿命LT高达399 h，比没有薄层的对比器件长1.7倍。