https://scholars.lib.ntu.edu.tw/handle/123456789/119625
標題: | 有機發光元件中功能性介面之研究 Engineering Functional Interfaces in Organic Light-Emitting Devices |
作者: | 陳介偉 Chen, Chieh-Wei |
關鍵字: | 有機發光元件;介面;OLED;interface | 公開日期: | 2005 | 摘要: | 由於有機發光元件適合應用於製作高效率、大面積之全彩顯示器,所以近年來受到廣泛的研究。在本論文中針對有機發光元件關鍵之元件介面及結構進行深入之研究及探討。 在本論文中,利用有機材料之間之交互擴散現象製作出雙色結構可重組、三色結構可重組之有機發光元件以及具有模糊接面之有機發光元件。結構可重組有機發光元件可在元件製作完成之後對元件加熱,進而調制元件之發光光色;我們更進一步研究對結構可重組有機發光元件局部加熱及圖形化的技術,而可以製作出具有紅、綠、藍發光光色之微細畫素。模糊接面有機發光元件較傳統異質接面元件具有較低之操作電壓及較高之發光效率,故我們利用模糊接面製作出具有高能量效率 (~20 lm/W) 之綠色螢光有機發光元件。 本論文提出可應用於上發光型有機發光元件之下電極陽極及下電極陰極結構。我們發現經由紫外線臭氧處理後之銀電極可作為上發光型有機發光元件之下電極陽極,其元件特性與使用氧化銦錫 (ITO) 作為陽極之傳統下發光型有機發光元件相當;我們更進一步提出不具有活性金屬材料之高反射下電極陰極結構,其利用在具高反射率之銀或鋁電極上製作一極薄之Alq-LiF-Al電子注入層結構,做為倒置結構上發光型有機發光元件之下電極陰極,我們也成功的地利用此一下電極陰極結構製作出高發光效率之倒置結構上發光型有機發光元件。 最後,本論文提出一新型、未使用活性金屬材料之堆疊型態有機發光元件的連接層結構,此連接層結構係於電子及電洞注入層間置入一極薄之金屬層,此金屬層具有提升元件之特性及穩定度之效果;此外,我們提出一模型來說明此連接層結構之工作原理,此模型也與光伏效應之量測結果相吻合。 Organic light-emitting devices (OLEDs) have been the subjects of intense investigation in recent years due to their applications in efficient, large-area and full-color displays. In OLEDs, characteristics of various interfaces are critical to device performances. This thesis studies structures and characteristics of various interfaces in OLEDs. By employing the interdiffusion between organic layers, we demonstrated the two-color reconfigurable, three-color reconfigurable, and fuzzy-junction OLEDs. In reconfigurable OLEDs, emission colors and device configurations could be altered after fabrication. The technique for fine patterning of color pixels through thermal imaging of such reconfigurable devices is also established. The fuzzy-junction OLEDs exhibit lower driving voltage and higher efficiency compared to conventional heterojunction OLEDs. High power efficiency (~20 lm/W) is observed in green fluorescent fuzzy-junction OLEDs. Effective structures of bottom electrodes, one anode structure and one cathode structure, are developed for top-emitting OLEDs. The uv-ozone treated Ag electrode was found to be an effective reflective anode structure for top-emitting OLEDs. The top-emitting devices with such surface-treated Ag anode show device characteristics competitive with those of a bottom-emitting device using the indium tin oxide anode. On the other hand, we developed a highly reflective bottom cathode for inverted top-emitting OLEDs. In such a cathode scheme, the ultrathin Alq-LiF-Al trilayer was used as an effective composite electron-injection layer for the Ag or Al bottom cathode in the inverted top-emitting OLEDs, involving no reactive metals during fabrication. Efficient inverted top-emitting OLEDs employing such a cathode scheme have been demonstrated. We also proposed a new connecting structure for tandem OLEDs without using reactive metals. With a middle metal layer sandwiched between electron- and hole-injection layers, the connecting structure substantially enhances the characteristics and operational stability of tandem devices. A model of the connecting structure in the tandem devices is proposed and the model is also consistent with the results of the photovoltaic measurements in the tandem OLEDs. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/50690 | 其他識別: | en-US |
顯示於: | 光電工程學研究所 |
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ntu-94-D90941005-1.pdf | 23.31 kB | Adobe PDF | 檢視/開啟 |
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