Kim Beomjin, Park Youngil, Park Jongwook
J Nanosci Nanotechnol. 2014 Nov;14(11):8449-52. doi: 10.1166/jnn.2014.9913.
A two-color white organic light-emitting diode (WOLED) with a co-host system in solution process method was demonstrated. The device configuration was ITO/PEDOT:PSS (40 nm)/emitting layer (50 nm)/TPBi (20 nm)/LiF (1 nm)/Al. The emitting layer consisted of TAT, (α- or β-) NPB, DPAVBi (blue dopant), and Rubrene (yellow dopant). The device using α-NPB or β-NPB showed a white color of CIE (0.29, 0.40) and (0.28, 0.39). The device using the α-NPB co-host showed a luminance efficiency of 3.39 cd/A, which is 21% higher than β-NPB (2.80 cd/A). Power efficiency was increased by 16% in α-NPB (2.34 Im/W) compared to β-NPB (2.02 Im/W). The Co-host emitter system of HTL and single blue emitter using a solution process for WOLED was shown before, but the HTL role was not understood clearly. From this study, the WOLED device efficiency can be attributed to the HTL's energy transfer property in the emitter mixing system.
展示了一种采用溶液法制备的具有共主体体系的双色白色有机发光二极管（WOLED）。器件结构为ITO/PEDOT:PSS（40纳米）/发光层（50纳米）/TPBi（20纳米）/LiF（1纳米）/Al。发光层由TAT、（α-或β-）NPB、DPAVBi（蓝色掺杂剂）和红荧烯（黄色掺杂剂）组成。使用α-NPB或β-NPB的器件显示出CIE坐标为（0.29, 0.40）和（0.28, 0.39）的白色。使用α-NPB作为共主体的器件的发光效率为3.39 cd/A，比β-NPB（2.80 cd/A）高21%。与β-NPB（2.02 Im/W）相比，α-NPB的功率效率提高了16%（2.34 Im/W）。之前已经展示过采用溶液法用于WOLED的HTL共主体发射体系统，但HTL的作用尚未被清楚理解。通过本研究，WOLED器件的效率可归因于发射体混合体系中HTL的能量转移特性。
