Concentration-insensitive and low-driving-voltage OLEDs with high efficiency and little efficiency roll-off using a bipolar phosphorescent emitter

详细信息    查看全文

• 作者：Tai Peng ; Guomeng Li ; Kaiqi Ye ; Shuo Huang ; Ying Wu ; Yu Liu ; ^{yuliu@jlu.edu.cn} ; Yue Wang
• 关键词：Electrophosphorescence ; Concentration-insensitive ; Bipolar iridium emitter
• 刊名：Organic Electronics
• 出版年：2013
• 出版时间：June, 2013
• 年：2013
• 卷：14
• 期：6
• 页码：1649-1655
• 全文大小：1281 K

文摘

A series of simplified trilayer phosphorescent organic light-emitting diodes (PHOLEDs) with high efficiency and little efficiency roll-off based on a bipolar iridium emitter Iridium(III) bis(2-phenylpyridinato)-m>Nm>,m>Nm>¡ä-diisopropyl-diisopropyl-guanidinate (ppy)₂Ir(dipig) has been demonstrated. They are dominated by the efficient direct-exciton-formation mechanism and show gratifying concentration-insensitive and low-driving-voltage features. In particular, very high and stable electroluminescence (EL) efficiencies (maximum power efficiency and external quantum efficiency >98 lm W^?1 and 25 % respectively, and external quantum efficiency >20 % over a wide luminance range of 1-15,000 cd m^?2) are achieved in the PHOLEDs based on emitting layers (EMLs) consisting of (ppy)₂Ir(dipig) codeposited with common host CBP in an easily controlled doping concentration range (15-30 wt % ). The EL performance of the PHOLEDs is comparable to the highest PHOLEDs reported in scientific literature.