高性能三重態-三重態湮滅上轉換藍色發光材料的開發及應用在有機發光二極體中的研究

Abstract

對於三重態三重態湮滅上轉換之藍色發光材料的研究，分別以下列兩個章節做敘述，分別為分子內鄰位兩個蒽發光基團的設計，以及單發光基團並引入咔唑取代的蒽衍生物：第一章中，我們合成了四種具有不同程度芳香環-芳香環 (Aryl-Aryl) 堆疊的雙蒽結構分子（An1、An2、An3、An4）。通過立體效應，我們的目標是最大程度地減小兩個蒽單元之間的距離，以最大化π-π相互作用。這種方法旨在觀察光物理行為的變化。此外，利用An4和環芳烷9的獨特光致變色和熱致變色性質，我們實現了可逆的分子內開環和閉環。於第二章，藉由第一章所得到的研究基礎，我們開發了三種咔唑取代的蒽衍生物：2CbzAn、26CbzAn和246CbzAn。這些結構中咔唑取代基的引入導致產生更多能量接近 2 x E(T1) 的三重態 E(Tm)，有效促進了三重態-三重態湮滅-上轉換 (TTA-UC) 過程，實現了更高的上轉換效率。不僅如此，隨著咔唑的引入，亦提高了螢光放光過程的效率 (PLQY)。在有機發光二極體元件的研究中，非摻雜狀態的元件展示了最高5.82%的外部量子效率(EQEmax)並展示了出色的純藍色發光（CIEy為0.101）。此外，DPaNIF摻雜的DMPPP/26CbzAn雙發光層(EML)結構的元件達到了相當不錯結果 (EQEmax=11.12%)。

In our research focusing on blue light-emitting materials based on triplet-triplet annihilation upconversion (TTA-UC), we have structured the study into two main chapters. The first chapter concentrates on intramolecular ortho-dianthracene designs, while the second chapter explores carbazole-based anthracene derivatives. In the first chapter of our study, we synthesized four molecules featuring varying degrees of aryl-aryl (Ar-Ar) stacking within di-anthracene structures (An1, An2, An3, An4). Utilizing steric effects, we aimed to minimize the distance between the two anthracene units to maximize π-π interactions. This approach was undertaken to observe changes in photophysical behavior. Additionally, leveraging the unique photochromism and thermochromism properties of An4 and cyclophane 9, we achieved reversible intramolecular ring-opening and closing. Building on the insights from Chapter 1, we developed three carbazole-substituted anthracenes: 2CbzAn, 26CbzAn, and 246CbzAn. The introduction of carbazole substituents in these structures resulted in the generation of more triplet states with energy levels near 2 x E(T1), effectively facilitating the TTA-UC process for a higher upconversion quantum yield. This finding aligns with the Adachi theory on TTA-UC mechanisms. In our OLED device studies, in its non-doped form, demonstrated a maximum external quantum efficiency (EQEmax) of 5.82% and exhibited exceptional pure-blue emission (CIEy of 0.101). Moreover, the OLED with a DPaNIF-doped DMPPP/26CbzAn bilayer structure achieved an impressive EQEmax of 11.12%, highlighting the potential of these materials in OLED applications.