以苯基咔唑系列分子建構的激發錯合體為主體系統實現高效率與低效率滾降磷光有機發光二極體

Using Phenylcarbazole-based Molecules in the Exciplex-Forming Co-Host System to Achieve High Efficient Phosphorescent OLEDs with Low Efficiency Roll-off

徐靖傑(Jing-Jie Xu)

指導教授 ： 陳志欣

淡江大學/理學院/化學學系碩士班/碩士(2021年)

https://doi.org/10.6846/TKU.2021.00081

摘要

本篇研究透過對二甲苯與間二甲苯做為π共軛橋梁連接兩個苯基咔唑。合成了五個分子，分別為PhCzp-Me、PhCNCzp-Me、PhCNCzp-MeCzPh、PhCzm-Me和PhCNCzm-MeCzPh。使用了理論計算得到對二甲苯與間二甲苯和苯基咔唑間的二面角分別為54.8°~55.7°和86.9°~91.4°。五個分子皆能與B3PymPM形成激發錯合體，並做為磷光材料Ir(ppy)2acac的共主體。其中以PhCNCzm-MeCzPh/B3PymPM形成的激發錯合體共主體的元件，最大外部量子效率達到31.5%，最大發射波長位於524 nm，CIE座標（0.316, 0.641）。這歸功於使用對二甲苯與間二甲苯連接苯基咔唑可以增加激發錯合體予體與受體間的距離，使激發錯合體的三重態能階提高。

關鍵字

激發錯合體 ； 磷光有機發光二極體 ； 電洞傳輸材料

並列摘要

In this work, five molecules constructed by linking two phenylcarbazole moieties with m-xylene or p-xylene as -linker, i.e., PhCzp-Me, PhCNCzp-Me, PhCNCzp-MeCzPh, PhCzm-Me and PhCNCzm-Me, were synthesized through metal-catalyzed coupling reactions. Density functional theory calculations showed that the dihedral angle of the molecules using p-xylene as -linker were 54.8°~55.7°, which are much smaller than that using m-xylene as -linker, that is, 86.9°~91.4°. All these molecules formed exciplex with B3PymPM and therefore they were applied to establish the exciplex-forming co-host OLED devices. The device applied PhCNCzm-MeCzPh/ B3PymPM as exciplex host for phosphorescence emitter Ir(ppy)2acac exhibited the largest EQE of 31.5% and the maximum emission wavelength of 524 nm with the CIE coordinate of (0.316, 0.641). The high EQE could be attributed to the higher triplet energy of exciplex caused by increase of intermolecular distance between donor and acceptor when m-xylene or p-xylene as -linker of the phenylcarbazole-based molecules.

並列關鍵字

Thermally Activated Delay Fluorescence ； Host Material ； Exciplex Donor ； Organic Light-Emitting Diode

參考文獻

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