PDF(Pubmed)
Abstract：
Extensive research has been dedicated to the solution-processable white organic light-emitting diodes (WOLEDs), which can potentially influence future solid-state lighting and full-color flat-panel displays. The proposed strategy based on WOLEDs involves blending two or more emitting polymers or copolymerizing two or more emitting chromophores with different doping concentrations to produce white light emission from a single layer. Toward this direction, the development of blends was conducted using commercial blue poly(9,9-di-n-octylfluorenyl2,7-diyl) (PFO), green poly(9,9-dioctylfluorenealt-benzothiadiazole) (F8BT), and red spiro-copolymer (SPR) light-emitting materials, whereas the synthesized copolymers were based on different chromophores, namely distyryllanthracene, distyrylcarbazole, and distyrylbenzothiadiazole, as yellow, blue, and orange-red emitters, respectively. A comparative study between the two approaches was carried out to examine the main challenge for these doping systems, which is ensuring the proper balance of emissions from all the units to span the entire visible range. The emission characteristics of fabricated WOLEDs will be explored in terms of controlling the emission from each emitter, which depends on two possible mechanisms: energy transfer and carrier trapping. The aim of this work is to achieve pure white emission through the color mixing from different emitters based on different doping concentrations, as well as color stability during the device operation. According to these aspects, the WOLED devices based on the copolymers of two chromophores exhibit the most encouraging results regarding white color emission coordinates (0.28, 0.31) with a CRI value of 82.
摘要：
广泛的研究致力于可溶液处理的白色有机发光二极管（WOLED），这可能会影响未来的固态照明和全彩平板显示器。所提出的基于WOLED的策略涉及将两种或更多种发射聚合物共混或将具有不同掺杂浓度的两种或更多种发射发色团共聚以从单层产生白光发射。朝着这个方向，共混物的开发是使用商业蓝色聚（9,9-二-正辛基芴基2,7-二基）（PFO）进行的，绿色聚(9,9-二辛基氟烷-苯并噻二唑)(F8BT),和红色螺环共聚物(SPR)发光材料，而合成的共聚物是基于不同的发色团，即二苯乙烯蒽，二苯乙烯基咔唑,和二苯乙烯苯并噻二唑，如黄色，蓝色,和橙红色发射器，分别。进行了两种方法之间的比较研究，以检查这些掺杂系统的主要挑战，这确保了所有单位的排放在整个可见光范围内的适当平衡。将在控制每个发射器的发射方面探索制造的WOLED的发射特性，这取决于两种可能的机制：能量转移和载流子捕获。这项工作的目的是通过基于不同掺杂浓度的不同发射器的颜色混合来实现纯白发射，以及设备操作期间的颜色稳定性。根据这些方面,例如,基于两种发色团的共聚物的WOLED器件关于具有82的CRI值的白色发射坐标(0.28,0.31)表现出最令人鼓舞的结果。
