吲哚苯並咪唑雙聚體及咔唑苯並咪唑雙聚體衍生物之合成、性質探討以及在有機發光二極體之應用

本篇論文利用吲哚苯並咪唑雙聚體(bis(indole-N-benzimidazole)) 及咔唑苯並咪唑雙聚體(bis(carbazole-N-benzimidazole)) 衍生物體為有機發光二極體中的主體材料，其中苯並咪唑具有促進電子傳遞及注入之特性，而咔唑本身則具有較高的三重態能階同時也具備良好的電洞傳導性質，因此選用此兩種分子做進一步的探討，而在之前的研究顯示，此兩種化合物利用碳氮鍵結相較於碳碳鍵結，碳氮鍵結可以使電子能有更佳分散效果，增加三重態能階，因此我們採用碳氮鍵結的方式來合成此系列化合物；另外，近年來吲哚在有機發光二極體之材料中也備受討論，因其同樣具有好的電洞傳遞能力以及高的三重態能階，因此本篇論文分為兩系列來討論，以這兩種傳電洞之材料在苯並咪唑(benzimidazole) 之不同位置做取代，討論位置對於整體材料之影響，同時增加化合物之分子量來提高熱穩定性。我們利用 X-ray 單晶繞射探討分子的排列及堆疊；以紫外-可見光光譜(UV-Vis)、螢光放射光譜(FL)、磷光放射光譜(Ph) 進行光物理性質探討；以循環伏安法(CV)、差式脈波伏安法(DPV) 進行電化學性質探討，並將所得之化合物作為主體發光材料摻混FIrpic 應用在藍色磷光有機發光二極體之元件製作上，而在元件的表現上，以化合物3dCBZB 為主體光材料的元件效率最佳，在電賀密度為20 mA/cm2 時的驅動電壓為6.70 V；於操作電壓為3.5V 時可達最大亮度16750 cd/m2、最大發光效率47.15 cd/A；於操作電壓為3V 時可達最大發光功率為46.57lm/W、最大外部量子效率達21.10 %。

關鍵字

苯並咪唑；咔唑；吲哚；雙偶極；主體發光材料；有機發光二極體(OLED)

並列摘要

In this thesis, we synthesized two series of compounds― bis(indole-N-benzimidazole) and bis(carbazole-N-benzimidazole) as the host materials in OLED. In this bipolar system, carbazole and indole groups which have high triplet energy and good hole-transporting ability as the hole-transporting moiety, and benzimidazole as the electron-transporting moiety. Directly connect two moieties and compare the effect of different substituted position. In addition, we increase molecular weights to improve their thermal stability. We have been performed Ultraviolete-visible (UV-vis) spectral, photoluminescence (PL) spectral, cyclic voltammetry (CV), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) measurements to investigate the photophysical properties, thermal properties and electrochemical properties of these materials. The results show that all these host materials have excellent thermal stability and maintain high triplet energy.The blue PhOLED device used this thesis compound as the host material and the compound 3dCBZB existed the best performance than other compounds in the device dopant 18% FIrpic. It exhibited the turn-on voltage at 20 mA/cm2 was 6.70V, maximum luminance value (16750 cd/m2), the maximum current efficiency (47.15 cd/A), the maximum power efficiency (46.57 lm/W), and the maximum external quantum efficiency (20.01 %).

並列關鍵字

benzimidazole ； carbazole ； indole ； bipolar ； OLEDs ； host materials

參考文獻

31. Shi, J.; Tang, C. W.; Chen, C. H., US Patent 5 1997, 646, 948.

2. Pope, M.; Kallmann, H. P.; Magnante, P., Electroluminescence in Organic Crystals. The Journal of Chemical Physics 1963, 38 (8), 2042-2043.

4. Tang, C. W.; VanSlyke, S. A.; Chen, C. H., Electroluminescence of doped organic thin films. Journal of Applied Physics 1989, 65 (9), 3610-3616.

6. Chihaya, A.; Shizuo, T.; Tetsuo, T.; Shogo, S., Organic Electroluminescent Device with a Tree-Layer Structure. Japanese Journal of Applied Physics 1988, 27 (4A), L713.

8. Holmes, R. J.; Forrest, S. R.; Tung, Y. J.; Kwong, R. C.; Brown, J. J.; Garon, S.; Thompson, M. E., Blue organic electrophosphorescence using exothermic host-guest energy transfer. Applied Physics Letters 2003, 82, 2422-2424.

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吲哚苯並咪唑雙聚體及咔唑苯並咪唑雙聚體衍生物之合成、性質探討以及在有機發光二極體之應用

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