雙功能性、偶極的喹咢啉中心模板之三芳香胺衍生物在小分子、高分子有機電致發光材料的研究

Abstract

我們開發出以喹咢啉 ( Quinoxaline ) 為骨架結合三芳香胺 ( Triarylamines ) 類衍生物作為有機電致發光材料，由於結合雙功能性 ( Bifunction ) 與偶極 ( Dipolar ) 的特性，使材料之間更能有效形成光激子 ( Exciton )，將推電子基團的七圓環三芳香胺片段與拉電子基團的喹咢啉片段搭配，形成具有1：1的接受-給予 ( Acceptor – Donor ) 電子系統 ( QLIMS; Q ) 的化合物之衍生物，在有機發光二極體小分子、高分子有機電致發光材料之研究。 本論文利用熱重分析儀評估其熱穩定性，發現有取代基的QLIMS這一系列化合物在熱穩定性上有不錯的表現。接著對此類化合物進行吸收、放射光譜、螢光量子產率的測量；同時也將利用循環伏安法評估其氧化還原行為和測定其HOMO-LUMO能階。發現此類化合物適合當作電洞傳輸兼發光層，並搭配合適的電子傳輸層製作發光二極體元件，並測量其光電性質。小分子綠光化合物在與Alq3搭配製成元件時，最大亮度可達12347 cd/m2；引入二苯胺基 ( Diarylamine ) 取代基使發光發光範圍調整至645 nm至675 nm，與Alq3搭配製成元件時，為一飽和的紅光材料，最大亮度可達10300 cd/m2。高分子化合物摻雜PVK導入PBD電子傳輸層製作高分子元件，能有效透過能量轉移放光，展現出良好的發光效率，最大亮度可達610 cd/m2。

Using Quinoxaline as template combined Triarylamines applied for the research of the organic light emitting diodes. Because of the characteristic of bi-functional and dipolar, they made that the materials could form exciton effectively. By taking advantage of the good electron affinitive property of quinoxlines and the efficient hole-injection/transporting property of triarylamines, we thought to hybridize them into a fused, tri-cyclic aromatic framework with a central 7-membered core (QLIMS). In addition, we thought to examine if the unique of mode of connection is influential to the structural, optical, morphological, redox, and optoelectronic profiles of the resulting materials. In marked contrast to common donor-acceptor based materials, this new type of bipolar compounds are dual functional and display unique optical, morphological, redox and optoelectronic propensities. In conjunction with a suitable electron-transporting material- Alq3, the type-I QLIMS serve as potential green electron-emitters in light-emitting devices. Remarkably, the Q-An also acts as a good hole-emitter, reaching a maximum EL intensity of 12347 cd/m2.The polymer doped PVK and combined a electron-transporting material-PBD can light by energy transferred. It showed good luminescent efficiency.