Molecular evolution of host materials by regular tuning of n/p ratio for high-performance phosphorescent organic light-emitting diodes†,Journal of Materials Chemistry C

当前位置： X-MOL 学术 › J. Mater. Chem. C › 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.)

Molecular evolution of host materials by regular tuning of n/p ratio for high-performance phosphorescent organic light-emitting diodes†
Journal of Materials Chemistry C ( IF 5.7 ) Pub Date : 2018-06-28 00:00:00 , DOI: 10.1039/c8tc02432d
Di Liu _{1,

2,

3,

4,

5} , Fang Wang _{3,

4,

5,

6} , Ruijuan Yao _{1,

2,

3,

4,

5}

Affiliation

By linking pyridine and 1,2,4-triazole as an electron-deficient group, two “dual n-type unit” bipolar host materials, namely 2-(3,5-di(9H-carbazol-9-yl)phenyl)-5-(1H-triazol-1-yl)pyridine (PyTzDCz) and 2-(3-(9H-carbazol-9-yl)phenyl)-5-(1H-triazol-1-yl)pyridine (PyTzSCz), and one bipolar reference compound 2-(3,5-di(9H-carbazol-9-yl)phenyl)pyridine (PyDCz) were designed and synthesized for use in phosphorescent organic light-emitting diodes (PhOLEDs). From the parent 1,3-bis(9H-carbazol-9-yl)benzene (mCP) via PyDCz and PyTzDCz to PyTzSCz, the molar ratio of n-type pyridine/triazole to p-type carbazole was regularly tuned as 0 : 2, 1 : 2, 2 : 2, and 2 : 1. With a regular increase of n/p ratio from 0 : 2 gradually to 2 : 1, the LUMO levels of these hosts are regularly deepened to enhance electron injection, and the turn-on voltages of their blue and green PhOLEDs are regularly decreased. Particularly, the PyTzSCz-hosted blue PhOLED turned on at 2.6 V with high power efficiency of 48.1 lm W⁻¹ (corresponding to an external quantum efficiency of 26.4% and a current efficiency of 45.9 cd A⁻¹), which is the lowest turn-on voltage so far and one of the highest power efficiencies reported for FIrpic PhOLEDs containing a single host. The PyTzSCz-hosted green device also exhibited low turn-on voltage of 2.4 V and high external quantum efficiency of 28.0%. This study manifests the molecular evolution trend of host materials from hole-transporting via bipolar to “dual n-type unit bipolar” for performance optimization.

中文翻译：

通过定期调节n / p比率可实现高性能磷光有机发光二极管主体材料的分子进化†

通过连接吡啶和1,2,4-三唑作为缺电子基团，两种“双n型单元”双极主体材料，即2-（3,5-二（9 H-咔唑-9-基）苯基）-5-（1 H-三唑-1-基）吡啶（PyTzDCz）和2-（3-（9 H-咔唑-9-基）苯基）-5-（1 H-三唑-1-基）吡啶（PyTzSCz）和一种双极性参考化合物2-（3,5-二（9 H-咔唑-9-基）苯基）吡啶（PyDCz）设计并合成用于磷光有机发光二极管（PhOLED）。从母体1,3-双（9 H-咔唑-9-基）苯（mCP）通过在PyDCz和PyTzDCz与PyTzSCz之间，n型吡啶/三唑与p型咔唑的摩尔比通常调整为0：2、1、2：2、2：2和2：1。从0：2到2：1的比例逐渐增加这些主体的LUMO含量，以增强电子注入，并定期降低其蓝色和绿色PhOLED的开启电压。特别是，承载PyTzSCz的蓝色PhOLED在2.6 V时开启，具有48.1 lm W ^-1的高功率效率（对应于26.4％的外部量子效率和45.9 cd A ^-1的电流效率），这是迄今为止包含单个主机的FIrpic PhOLED的最低开启电压，也是报道的最高功率效率之一。PyTzSCz托管的绿色设备还具有2.4 V的低启动电压和28.0％的高外部量子效率。这项研究表明了基质材料的分子演化趋势，即从空穴通过双极传输到“双n型单元双极”以优化性能。

更新日期：2018-06-28

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