摻雜型雙主發光體系統之高效率有機電激發光元件

Abstract

在本篇論文中，我們發展了高效率紅色有機電機發光元件，將之應用於螢光性染料4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetra- methyl-julolidyl-9-enyl)-4H-pyran（DCJTB）摻雜於9,10-di(2-naphthyl) anthracene (ADN) / Alq3所構成的雙主發光體系統元件中，可以獲得在操作電流20 mA/cm2下，發光效率高達4.2-5.5 cd/A，並且色調達CIEx,y=[0.64, 0.35]-[0.62, 0.37]的飽和紅光元件。在ADN濃度高於60%時，ADN/Alq3構成雙主發光層體的元件，成功排除了原先在高趨動電流時會損失發光效率的問題，以致能夠獲得穩定的發光效率（cd/A）與操作電流密度（J）相對關係之曲線，並且消除在典型元件的異質介面所存在電荷累積的問題進而大幅地改善元件的穩定度。

In this thesis, we have developed an efficient red OLED device based on the fluorescent dye 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetra- methyl-julolidyl-9-enyl)-4H-pyran (DCJTB) doped in a novel co-host emitter system of 9,10-di(2-naphthyl) anthracene (ADN) and Alq3, which achieved a luminance efficiency of 4.2– 5.5 cd/A at 20 mA/cm2 with a CIEx,y color coordinate of [0.64, 0.35] – [0.62, 0.37]. At high ADN concentration (>60%), this co-hosted emitter system possessed the advantage of alleviating the current-induced fluorescence quenching problem often encountered in red organic EL devices and greatly improved the EL efficiency over a wide range of drive current conditions. This novel composition of co-host emitter also significantly improved the device lifetime which is attributed to the elimination of the heterointerface present in conventional devices that greatly affects the device reliability.