使用Alq3電子傳輸層於高分子發光二極體之增強發光亮度與效率

本文係研究將電子傳輸層（Alq3）材料插入介於陰極（Al）與發光層（PF）之間有助於改善高分子發光二極體的電致發光效率。當切入電壓於2.5伏特時有插入Alq3層的元件電致發光效能比起未使用Alq3層元件顯現出大幅改善，當插入Alq3的厚度為10m時會導致高分子發光二極體（PLED）載子傳輸有個平順的能障高度，提升電子注入於陰極，而且Alq3的表面平均粗糙度有最小的數值約為0.790nm。另外，插入Alq3層的發光之驅動電壓為5伏特有3.51 cd/m2的亮度，而最大的發光亮度為361.8 cd/m2，元件發光面積為1.5×0.3 cm2。元件的色度放射出黃綠光為536mn，而CIE色譜圖為(0.39, 0.57）。

We report that an electron-transporting layer of Alq3 is interposed between a cathode of Al and an emissive layer of Polyfluorene (PF) which can significantly improve electroluminescence efficiency in a polymer light emitting diode (PLED). The difference of the turn-on voltage is about 2.5 V for with and without insertion of a thin Alq3 layer, which greatly improves the EL performance compared with the devices without an Alq3 layer. The thickness of Alq3 is 10 nm, which is resulted in the smooth energy barrier height on PLED and promoted electron injection in the cathode section. The average surface roughness of Alq3 under thickness 10 nm is the smallest about 0.790 nm. Besides, the turn-on voltage of luminescence with Alq3 defined by 3.51 cd/m2 is 5 V. A maximum luminescence is obtained at 361.8 cd/m2. The emission area is 1.5×0.3 cm2. The devices show the yellow-green light emission with a peak at about 536 nm. The color coordinate in CIE chromaticity is (0.39, 0.57).