Highly Efficient Warm White Organic Light-Emitting Diodes by Triplet Exciton Conversion
Highly Efficient Warm White Organic Light-Emitting Diodes by Triplet Exciton Conversion
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DOI：
10.1002/adfm.201201858
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发表时间：
2013-02-11
影响因子：
19
通讯作者：
Lu, Zhenghong
中科院分区：
文献类型：
--
作者：
Chang, Yi-Lu;Song, Yin;Lu, Zhenghong
白色有机发光二极管（WOLEDs）作为替代白炽灯和荧光灯的新一代光源，目前正在世界范围内进行深入的研究和开发。WOLEDs面临的主要挑战之一是同时实现高能效和高显色指数，以使该技术与其他替代技术（如无机led）竞争。本文提出了一种全磷光体四色WOLEDs，采用一种新颖的器件设计原理，利用分子能量转移，特别是在级联发射区配置的普通有机层内的三重态激子转换，以实现卓越的性能：使用标准磷光体，在1000 cd/m2时，外部量子效率（EQE）为24.5%，显色指数（CRI）为81，在5000 cd/m2时，EQE为20.4%，CRI为85。该EQEs是迄今为止报道的具有如此高显色指数的单或多发射体WOLEDs中最高的，这代表了在固态照明中实现WOLEDs的重要一步。
White organic light-emitting diodes (WOLEDs) are currently under intensive research and development worldwide as a new generation light source to replace problematic incandescent bulbs and fluorescent tubes. One of the major challenges facing WOLEDs has been to achieve high energy efficiency and high color rendering index simultaneously to make the technology competitive against other alternative technologies such as inorganic LEDs. Here, an all-phosphor, four-color WOLEDs is presented, employing a novel device design principle utilizing molecular energy transfer or, specifically, triplet exciton conversion within common organic layers in a cascaded emissive zone configuration to achieve exceptional performance: an 24.5% external quantum efficiency (EQE) at 1000 cd/m2 with a color rendering index (CRI) of 81, and an EQE at 5000 cd/m2 of 20.4% with a CRI of 85, using standard phosphors. The EQEs achieved are the highest reported to date among WOLEDs of single or multiple emitters possessing such high CRI, which represents a significant step towards the realization of WOLEDs in solid-state lighting.