含咔啉之矽苯衍生物合成、性質探討及其在藍色磷光有機發光二極體之應用

Abstract

我們設計了一系列以tetraphenylsilane分子為中心，嘗試藉由控制咔唑 (carbazole) 及咔啉 (carboline) 基團數目以平衡主發光體中電子電洞對之傳輸速率。除此之外，亦比較了不同位置氮原子對磷光有機發光二極體元件表現的影響。利用矽苯基阻斷分子共軛系統，可成功維持主發光體材料所需的高三重態能隙，並具備高熱穩定性的優點。我們同時針對這系列化合物進行光物理及電化學性質的比較與探討，並將所得之主體摻雜客發光體FIrpic，應用於藍色磷光有機發光二極體元件的製作。結果顯示一系列咔啉因結構差異，造成主發光體在螢光及磷光放射光譜之差別，亦表現於電化學性質上。而在元件表現上，以化合物12為主發光體的藍光元件表現最佳，在電荷密度20 mA/cm2時的驅動電壓為 7.71 V；於操作電壓3.5 V時可達最大亮度13280 cd/m2，最大發光效率56.08 cd/A，最大發光功率50.04 lm/W，最大外部量子效率為26.02%。

We synthesized a series of carboline derivatives combined with tetraphenylsilane as host materials for blue phosphorescent organic light emitting diodes. In this thesis, we introduce tetraphenylsilane group to interrupt the conjugation length,and expect to maintain the high triplet energy and stable thermal properties. Additionly,we try to balance the electron and hole transporting abilities by adjusting the group numbers of carboline and carbazole.We also want to figure out the effect of position of nitrogen in carboline how to affect the device performance of PhOLED. The difference reflects on photophysical and electrochemical properties are also discussed. The PhOLED device shows that compound 12 as host material exists the better performance than other compounds in the device dopant 21% Firpic.It exhibitied the turn-on voltage at 20 mA/cm2 was 7.71 V, maximum luminance value (13280 cd/m2), the maximum current efficiency (56.08 cd/A), the maximum power efficiency (50.04 lm/W),and the maximum external quantum efficiency (26.02 %).