New Ambipolar Blue Emitting Materials Based on Amino Coumarin Derivatives with High Efficiency for Organic Lightemitting Diodes
作者:Seungho Kim、Kyung Jin Lee、Beomjin Kim、Jaehyun Lee、Kwang-Yol Kay、Jongwook Park
DOI:10.1166/jnn.2013.8151
日期:2013.12.1
New blue emitting materials, 7-diphenylamino-4-methyl-coumarin (DPA-MC) and aminotri(4-methylcoumarin) (T-MC) including coumarin moiety were synthesized by Ullman reaction. Optical and electronic properties were examined by UV-Vis. Absorption spectrum, PL spectrum, and cyclic voltammetry. UV-Vis. spectra of DPA-MC and T-MC in a film state showed maximum absorption wavelengths of 382 nm and 399 nm, respectively. PL spectra of DPA-MC and T-MC show maximum emission wavelengths of 463 nm and 481 nm respectively. Non-doped OLED devices were fabricated by using the synthesized materials as an emitting material layer. DPA-MC compound showed highly efficient luminescence properties. EL spectrum of DPA-MC exhibited a maximum value of 463 nm and DPA-MC device provided luminescence efficiency of 3.83 cd/A, power efficiency of 2.46 lm/W, external quantum efficiency of 3.71% and CIE coordinates of (0.154, 0.190) at a current density of 10 mA/cm2. In particular, Power efficiency increased by more than 1.6 times in DPA-MC (2.46 lm/W), which is higher than commercialized material, DPVBi (1.46 lm/W). High EL performance might come from ambipolar effects of a molecular structure.
通过乌尔曼反应合成了新型蓝色发光材料--7-二苯基氨基-4-甲基香豆素(DPA-MC)和含有香豆素分子的氨基三(4-甲基香豆素)(T-MC)。紫外可见光检测了它们的光学和电子特性。吸收光谱、PL 光谱和循环伏安法检测其光学和电子特性。薄膜状态下的 DPA-MC 和 T-MC 的紫外可见光谱的最大吸收波长分别为 382 纳米和 399 纳米。DPA-MC 和 T-MC 的聚光光谱显示最大发射波长分别为 463 纳米和 481 纳米。利用合成材料作为发光材料层,制造出了非掺杂有机发光二极管器件。DPA-MC 化合物显示出高效的发光特性。在电流密度为 10 mA/cm2 时,DPA-MC 器件的发光效率为 3.83 cd/A,功率效率为 2.46 lm/W,外部量子效率为 3.71%,CIE 坐标为(0.154, 0.190)。其中,DPA-MC 的功率效率提高了 1.6 倍多(2.46 lm/W),高于商业化材料 DPVBi(1.46 lm/W)。高电致发光性能可能来自分子结构的伏极效应。