小分子溶液製程低溶解度藍光螢光與高效率Os(II)紅光磷光有機發光二極體

Abstract

本論文以刮刀塗佈技術配合基板加熱溫度成功塗佈低溶解度之小分子有機溶液後，以EB47及EB515之主客發光體材料，搭配高揮發性溶劑與不同電荷傳輸層材料進行藍光螢光有機發光二極體元件製作，比較不同元件結構之差異並改善輕微互溶，再調變膜層厚度，最佳的元件結構是以VB-FNPD作為電洞傳輸層搭配電子傳輸層TPBi，其電流效率最高可達3.4 cd/A，外部量子效率1.6%，亮度8,100 cd/m2。另外，以文獻中相同的元件結構及製程製作紅光磷光有機發光二極體，僅將原為真空蒸鍍之電子傳輸層改以刮刀塗佈之溶液製程，最佳化氟化銫膜層厚度後，以TCTA及Os(II) complex 2為主、客發光體之元件，其電流效率最高為7.7 cd/A，外部量子效率6.6%，亮度920 cd/m2，元件效率達文獻製程之四成以上。

The dissertation aims to successfully coat small molecule organic solution of low solubility by blade coating on a hot plate at different temperature, and fabricate blue fluorescence organic light-emitting diode with volatile solvent and different charge transporting layers in host-guest system of EB47 and EB515. We compared the variations in different device structures, and reduced the slight dissolution before tuning various thicknesses of organic films. The optimal device structure is 2,7-disubstituted fluorene-based triaryldiamine (VB-FNPD) and 2,2',2"-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi) as hole transporting layer and electron transporting layer, respectively. Current efficiency of 3.4 cd/A, and external quantum efficiency of 1.6%, and luminance of 8,100 cd/m2 are achieved in this device structure. In the other experiment, we fabricated red phosphorescence organic light-emitting diodes in the same device structure and process of literature. The only variation is electron transporting layer coated by blade-only technique in place of evaporating in vacuum. After optimizing the thickness of CsF, current efficiency of 7.7 cd/A, and external quantum efficiency of 6.6%, and luminance of 920 cd/m2 are achieved in host-guest system of 4,4',4"-tris-(N-carbazolyl)-triphenylamine (TCTA) and [Os(btfp)2(pp2b)] (Osmium complex 2). The efficiency is over 40 percent of original evaporation process.