高效黄色电致发光的四个铱（III）配合物与苯并[d]噻唑衍生物作为主要配体。

Efficient yellow electroluminescence of four iridium(iii) complexes with benzo[d]thiazole derivatives as main ligands.

机构信息

State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China.

出版信息

Dalton Trans. 2018 Jun 19;47(24):8032-8040. doi: 10.1039/c8dt01479e.

DOI:10.1039/c8dt01479e

PMID:29872814

Abstract

Four bis-cyclometalated iridium(iii) complexes, (bt)2Ir(tpip), (fbt)2Ir(tpip), (cf3bt)2Ir(tpip) and (dfbt)2Ir(tpip) (bt = 2-phenylbenzo[d]thiazole, fbt = 6-fluoro-2-phenylbenzo[d]thiazole, cf3bt = 2-phenyl-6-(trifluoromethyl)benzo[d]thiazole, dfbt = 5,7-difluoro-2-phenylbenzo[d]thiazole, tpip = tetraphenylimidodiphosphinate) have been synthesized and investigated. All complexes emit yellow light peaks at 564-574 nm with quantum efficiencies (Φem) of 27.1-48.4% and excited state lifetimes of 2.40-2.81 μs in degassed CH2Cl2 solution at room temperature. Correspondingly, organic light-emitting diodes (OLEDs) using these complexes as emitters achieve yellow electrophosphorescence with good device characteristics. Due to its highest photoluminescence quantum yield (48.4%), the device based on (dfbt)2Ir(tpip) displays the best device performance with a maximum current efficiency (ηc, max) of up to 69.8 cd A-1 and a maximum external quantum efficiency (EQEmax) of up to 24.3%. Furthermore, all devices showed low efficiency roll-off ratios. The EQE could still be retained at 17.7%, 16.4%, 18.3% and 20.6% for four devices at a luminance of 1000 cd m-2. These results suggest that these materials have potential application in efficient OLEDs.

摘要

四种双环金属铱（III）配合物，（bt）2Ir（tpip），（fbt）2Ir（tpip），（cf3bt）2Ir（tpip）和（dfbt）2Ir（tpip）（bt = 2-苯基苯并[d]噻唑，fbt = 6-氟-2-苯基苯并[d]噻唑，cf3bt = 2-苯基-6-（三氟甲基）苯并[d]噻唑，dfbt = 5,7-二氟-2-苯基苯并[d]噻唑，tpip = 四苯基咪唑二膦酸酯）已被合成并进行了研究。所有配合物在室温下的真空 CH2Cl2 溶液中发射出 564-574nm 的黄色光峰，量子效率（Φem）为 27.1-48.4%，激发态寿命为 2.40-2.81μs。相应地，使用这些配合物作为发射器的有机发光二极管（OLED）实现了良好器件特性的黄色电磷光。由于其最高的光致发光量子产率（48.4%），基于（dfbt）2Ir（tpip）的器件显示出最佳的器件性能，最大电流效率（ηc，max）高达 69.8cd A-1，最大外量子效率（EQEmax）高达 24.3%。此外，所有器件均表现出低效率滚降比。在亮度为 1000cd m-2 时，四个器件的 EQE 仍可分别保持在 17.7%、16.4%、18.3%和 20.6%。这些结果表明，这些材料在高效 OLED 中有潜在的应用。