高反射率與高導電率的雙層式陽極應用在上發光有機發光二極體

Abstract

我們利用上發光結構有機發光二極體的微共振腔效應增強元件的效率，用新穎的雙層陽極Al/ITO，同時兼具高反射率與高導電性，能階上的匹配成功幫助上發光元件有好的電洞注入特性能夠降低操作電壓，最後優化元件的光學條件讓各種元件光色更為飽和，滿足目前顯示器廣色域的需求。我們也試圖研發出上發光的白光，我們還利用簡單的光學原理，在元件外增加了一層附蓋層(capping layer)增加了半穿透陰極的穿透率，不但降低了微共振腔效應也保護金屬不受外力刮傷，成功發展出一個寬波寬的雙波段高效率上發光白光，在20 mA/cm2條件下達亮度有3000 nits，電流效率到達13 cd/A，CIEx,y色座標在(0.30,0.39)，屬於高色溫的白光。

We demonstrate efficient top organic light emitting diodes (TOLED) with microcavitty effect using a novel high reflective and high conductive bilayer anode. The novel bilayer Al/ITO anode with which the sputtered-ITO thin layer is found to improve the hole injection into the organic hole-transport layer. Finally, we had optimized the single color devices to provide greater brightness and larger color gamut in TOLEDs. In addition, by capping with a transparent organic layer of NPB on the semitransparent cathode to enhance transparency of cathode while suppressing the undesirable microcavity effect, a broadband white emission can be achieved. The dichromatic WTOLEDs with two adjacent fluorescent blue/yellow emissive layers can achieve an EL efficiency of 13.7 cd/A at high luminance of 3,000 cd/m2 and a low driving voltage of 5.9 V with a Commission Internationale d’Eclairage (CIE) coordinates of (x＝0.30, y＝0.39).