Highly efficient orange and deep-red organic light emitting diodes with long operational lifetimes using carbazole-quinoline based bipolar host materials
Highly efficient orange and deep-red organic light emitting diodes with long operational lifetimes using carbazole-quinoline based bipolar host materials
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DOI：
10.1039/c4tc00523f
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发表时间：
2014-08-14
影响因子：
6.4
通讯作者：
Cheng, Chien-Hong
中科院分区：
文献类型：
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作者：
Chen, Chin-Hsien;Hsu, Lun-Chia;Cheng, Chien-Hong
橙色和深红色发光有机发光二极管(PhOLED)对于OLED显示屏和照明非常重要；然而，专为橙色/深红色PhOLED设计的高性能和长工作寿命的主机非常少见。合成了三种新型咔唑-喹啉杂化材料，并将其作为橙色和深红色有机电致发光的主体材料。这些双极主体表现出90-146摄氏度的高玻璃化转变温度和2.51-2.95 eV的三重态能隙。以9-(4-(4-phenylquinolin-2-yl)phenyl)-9H-carbazole(CHPPQ)为基质的橙色光致发光器件的最高外量子效率为25.6%，功率效率为68.1lmW-1，是橙色光致发光器件中的最高值。更重要的是，橙色和深红色设备的效率下降都非常小。例如，橙色器件在100cdm(-2)和1000cdm(-2)下的EQE分别为251%和23.6%；这一结果似乎是迄今为止橙色PhOLED的最低效率滚动。此外，在初始亮度为500cdm(-2)时，橙色和深红色器件的工作寿命分别超过26412h和11450h。这些值比使用CBP作为主机的相应设备的值长12倍(橙色)和6倍(红色)。
Orange and deep red-emitting phosphorescent organic light-emitting diodes (PhOLEDs) are important for OLED displays and lighting; however, high-performance with long operational lifetime hosts designed for orange/deep red PhOLEDs are very rare. Three new carbazole-quinoline hybrids are synthesized and used as the host materials for orange and deep-red PhOLEDs. These bipolar hosts show high glass transition temperatures of 90-146 degrees C and triplet energy gaps of 2.51-2.95 eV. The optimized orange PhOLEDs using 9-(4-(4-phenylquinolin-2-yl)phenyl)-9H-carbazole (CzPPQ) as the host show the highest external quantum efficiency (EQE) of 25.6% and a power efficiency of 68.1 lm W-1, which are the highest values for orange PhOLEDs. More importantly, the efficiency roll-off is extremely small for both the orange and deep-red devices. For example, an orange device showed an EQE of 25.1% at 100 cd m(-2) and 23.6% at 1000 cd m(-2); the result appears to be the lowest efficiency roll-off for orange PhOLEDs to date. Additionally, the operational lifetime of both the orange and deep-red devices gave a T-50 of more than 26 412 and 11 450 h, respectively, at an initial luminance of 500 cd m(-2). The values are 12 times (orange) and 6 times (red) longer than those of the corresponding devices using CBP as the host.