设计合理的发光层主客体掺杂结构是获得高效率磷光白色有机发光器件(WOLEDs)的必要条件。将橙色磷光染料PO-01和蓝色磷光染料FIrPic分别掺入空穴传输材料mCP和电子传输材料TmPyPB中,制备了低效率滚降、发光颜色稳定的双发光层结构暖白光器件。通过器件结构的优化设计,促进了载流子注入平衡,使激子分布在较宽区域,呈现较低的发光效率滚降。器件的最大电流效率为17.8cd/A,当发光亮度为1000cd/m2时,电流效率滚降仅为5.6%。当发光亮度从22.4cd/m2增至7293cd/m2,相应的发光色坐标从(0.406,0.464)变化至(0.405,0.458),变化量ΔCIE仅为(0.005,0.004)。
White organic light-emitting diodes (WOLEDs) are one of the most promising candidates for solid-state lighting sources and displays due to their inherent merits of high efficiency,flexibility,light weight and fast response time.With the development of organic materials and device structures,the performance of WOLEDs has been gradually enhanced to satisfy the demand of real commercialization.The strategic design of device structures was applied to simultaneously realize the superior color stability,high efficiency,and low efficiency roll-off properties of phosphorescent WOLEDs.The optimized WOLED emited the forward-viewing maximum current efficiency (CE) of 17.8cd/A,and the CE still remain 16.8cd/A at 1000cd/m2,exhibiting extremely low efficiency roll-off.Furthermore,the devices also shown extremely stable CIE coordinate varying range of (0.005,0.004) from 22.4 to 7293cd/m2.The good performances indicated the validity of the structure design and provided an effective way for the development of high-performance WOLEDs.
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