"9,10-蒽衍生物之合成、性質探討與其在藍色有機發光二極體材料之應用"

Abstract

本篇論文合成了一些以 9,10 號碳蒽取代之衍生物，分別以苯並咪唑與噁二唑進行單邊取代，另以苯並咪唑進行雙邊取代，最後在一個分子上修飾兩個蒽取代基，藉由這些設計試著去提高分子的電子移動速率與提高TTA-UC 的效率，以利我們的分子應用在螢光發光材料上。 透過電化學測試與光物理測試，得知我們所合成之化合物，能階差約在 2.8eV 到3.0 eV，螢光放光在藍光範圍(~430 nm)，在熱穩定性分析裡，大多數的化合物都符合蒸鍍過程的熱穩定條件，我們也做了溶液中的TTA-UC 測試，以綠光成功激發出藍光，並與光物理分析的光譜圖互相呼應。 在元件表現的部分，我們將所得之化合物，摻混入PVK 中以旋轉塗佈的方式製作有機發光二極體元件，跟市售TTA-UC 材料DPA 比較，我們的化合物在修飾上拉電子基團後，能具有更良好的電子傳輸特性，在以化合物2 為發光材料的簡易雙層元件中，最高亮度為319 cd/m2，最大電流效率為0.40 cd/A。另也將化合物2、3、6 以蒸鍍法製作元件，在元件架構尚未最佳化前，測試結果最大亮度可達3869 cd/m2，最大電流效率為1.69 cd/A，最大外部量子效率為0.63%，在暫態螢光測試裡，化合物2、3 比市售材料ADN 有更好的延遲螢光表現，足以證明其在OLED 的應用潛力。

We have synthesized a family of anthracene derivatives with substitutions on the C-9 and C-10 positions. Anthracene derivatives could be activated by less energy and produced a higher S1 excited state. Therefore, we could get the higher frequency emission than we excite them directly. This phenomenon is also called triplet-triplet annihilation photon upconversion (TTA-UC). We utilize substitutions on anthracene in order to tune more appropriate energy level match between our light emitter layer (EML) and electron/hole transporting layers (ETL/HTL). By introducing these substituted groups, it can be facilitated the electron/hole-transporting ability of anthracene. Meanwhile, the higher molecular weight, the better thermal stabilities. We used cyclic voltammetry to characterize our target compound, their energy gap are between 2.8 eV to 3.0 eV approximately. From fluorescence and phosphorescence spectra, most of them could emit blue light by the TTA-UC process. We also make some PLED devices to analyze their photoelectric properties. Our compounds have higher electron mobility than DPA and possess great current efficiency. From OLED devices which are composed by vapor deposition, we could get the highest current efficiency of 1.69 cd/A at 6 V, the highest power efficiency of 0.92 lm/W at 5.5 V, the highest luminance of 3869 cd/m2 at 10 V, the largest EQE of 0.63% at 6 V. According to these outcome, we can make a conclusion that our compound have excellent potential to be the light emitting materials compared to DPA and ADN.