Boosting the Efficiency of Near‐Infrared Fluorescent OLEDs with an Electroluminescent Peak of Nearly 800 nm by Sensitizer‐Based Cascade Energy Transfer,Advanced Functional Materials

当前位置： X-MOL 学术 › Adv. Funct. Mater. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Boosting the Efficiency of Near‐Infrared Fluorescent OLEDs with an Electroluminescent Peak of Nearly 800 nm by Sensitizer‐Based Cascade Energy Transfer
Advanced Functional Materials ( IF 18.5 ) Pub Date : 2018-03-07 , DOI: 10.1002/adfm.201706088
Tengxiao Liu ₁ , Guohua Xie ₁ , Cheng Zhong ₁ , Shaolong Gong ₁ , Chuluo Yang _{1,

2}

Affiliation

A sensitization‐based cascade energy transfer channel is proposed to boost the electroluminescent performances of the solution‐processed near‐infrared organic light‐emitting devices (OLEDs) featuring an electroluminescent peak of 786 nm from a new fluorescent emitter of N⁴,N⁴,N⁹,N⁹‐tetra‐p‐tolylnaphtho[2,3‐c][1,2,5]thiadiazole‐4,9‐diamine (NZ2mDPA) with unique aggregation‐induced emission (AIE) property. The optimized device is composed of 4,4′‐N,N‐dicarbazole‐biphenyl (CBP) as the host, bis(2‐phenyl‐1,3‐benzothiozolato‐N,C^2′)iridium (Ir(bt)₂(acac)) as the sensitizer, and NZ2mDPA as the emitter, where the cascade energy transfer can occur via two steps realizing unexpected triplet–singlet energy transfer by the Förster mechanism. The first step features efficient triplet harvesting from CBP to Ir(bt)₂(acac), and then the second step involves in resonant energy transfer from the phosphorescent sensitizer to the near‐infrared AIE emitter of NZ2mDPA, which finally endows two channels of harvesting singlet and triplet excitons. The unique scheme achieves not only more efficient Förster energy transfer but also the higher utilization efficiency of triplet excitons. As a result, the near‐infrared OLEDs can realize a factor of 2.7 enhancement of external quantum efficiency by employing the phosphor‐sensitized AIE lumogen compared with the commonly used binary host–guest system.

中文翻译：

通过基于敏化器的级联能量转移提高近800 nm的电致发光峰的近红外荧光OLED的效率

提出了一种基于增感的级联能量传输通道，以提高固溶处理的近红外有机发光器件（OLED）的电致发光性能，该器件的新发光源为N ⁴，N ⁴，其电致发光峰为786 nm 。N ⁹，N ^9-四对甲苯甲酚[2,3- c ] [1,2,5]噻二唑-4,9-二胺（NZ2mDPA）具有独特的聚集诱导发射（AIE）特性。优化的设备由4,4'- N，N-二咔唑-联苯（CBP）作为主体，双（2-苯基-1,3-苯并噻唑并N，C ^2'）铱（Ir（bt）₂（acac））作为敏化剂，NZ2mDPA作为发射体，其中级联能量传递可通过两步实现，这是通过福斯特机制实现了三重态-单重态能量的意外传递。第一步是从CBP到Ir（bt）_2进行有效的三重态收获（acac），然后第二步涉及将共振能量从磷光敏化剂转移到NZ2mDPA的近红外AIE发射器，该发射器最终提供了两个收获单重态和三重态激子的通道。独特的方案不仅实现了更有效的Förster能量传输，而且实现了三重态激子的更高利用效率。结果，与常用的二进制主-客体系统相比，通过使用磷光敏化的AIE发光体，近红外OLED可以实现外部量子效率提高2.7倍。

更新日期：2018-03-07

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11