Ji Wenyu, Tian Ye, Zeng Qinghui, Qu Songnan, Zhang Ligong, Jing Pengtao, Wang Jia, Zhao Jialong
State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences , Changchun 130033, China.
ACS Appl Mater Interfaces. 2014 Aug 27;6(16):14001-7. doi: 10.1021/am5033567. Epub 2014 Jul 23.
The performances and spectroscopic properties of CdSe/ZnS quantum dot light-emitting diodes (QD-LEDs) with inserting a thickness-varied 1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene (TPBi) layer between the QD emission layer and 4,4-N,N-dicarbazole-biphenyl (CBP) hole transport layer (HTL) are studied. The significant enhancement in device peak efficiency is demonstrated for the device with a 3.5 nm TPBi interlayer. The photoluminescence lifetimes of excitons formed within QDs in different devices are also measured to understand the influence of electric field on the QD emission dynamics process and device efficiency. All the excitons on QDs at different devices have nearly the same lifetime even though at different bias. The improvement of device performance is attributed to the separation of charge carrier accumulation interface from the exciton formation zone, which suppresses exciton quenching caused by accumulated carriers.
研究了在量子点发光二极管（QD-LED）的量子点发射层与4,4-N,N-二咔唑联苯（CBP）空穴传输层（HTL）之间插入厚度可变的1,3,5-三（N-苯基苯并咪唑-2-基）苯（TPBi）层时，其性能和光谱特性。对于具有3.5 nm TPBi中间层的器件，其器件峰值效率有显著提高。还测量了不同器件中量子点内形成的激子的光致发光寿命，以了解电场对量子点发射动力学过程和器件效率的影响。即使在不同偏压下，不同器件中量子点上的所有激子寿命几乎相同。器件性能的提高归因于电荷载流子积累界面与激子形成区的分离，这抑制了由积累载流子引起的激子猝灭。
