以電洞遷移率抑制層提升藍光有機發光元件效率

本實驗使用多層電洞遷移率抑制層[(NPB/MTDATA)n，hole mobility restraint layer (HMRL)]來製作藍光有機發光元件，元件結構為ITO/MTDATA/NPB(XÅ)/MTDATA(YÅ)/NPB(600-X-Y)Å/BCP/Alq/LiF/Al。首先探討NPB和MTDATA的厚度對元件特性的影響，在此部分可觀察到當NPB和MTDATA的厚度分別在50 Å和100 Å時，元件的特性較佳。接著再以所得NPB及MTDATA之最佳厚度，繼續探討多層電洞遷移率抑制層對元件特性的影響，元件結構為ITO/MTDATA/[NPB(50Å)/MTDATA(100Å)n/NPB(600-150×n)Å/BCP/Alq/LiF/Al，在此部分可觀察到n=3，元件特性最佳，它的發光光譜峰值與傳統藍光元件一樣位於425nm，而其發光效率為傳統藍光元件的1.6倍

OLEDs with hole mobility restraint layers (HMRL) are fabricated. The structure of the device is ITO/MTDATA/NPB(XÅ)/MTDATA(YÅ)/NPB(600-X-Y)Å/BCP/Alq/LiF/Al. The dependence of the thickness of NPB and MTDATA on OLEDs characteristics has been discussed. The characteristics have been improved when the thickness of NPB and MTDATA is 50Å and 100Å, respectively. The value of n in HMRL (NPB/MTDATA)n is also discussed. When n is 3, the emission peak of OLEDs is around 425nm and its luminance efficiency is 1.6 times the conventional blue devices.