Chang Yu-Fan, Yang Lan-Sheng, Su Hsiao-Tso, Liao Si-Yi, Niu Mu-Chun, Mahesh K P O, Chen Chao-Hsuan, Chao Yu-Chiang, Meng Hsin-Fei, Huang Heh-Lung, Chao Teng-Chih, Tseng Meu-Rurng, Luo Chih-Wei, Zan Hsiao-Wen, Horng Sheng-Fu
Institue of Physics, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan.
Department of Electrophysics, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan.
Chempluschem. 2019 Sep;84(9):1375-1383. doi: 10.1002/cplu.201900248. Epub 2019 Jun 4.
The instability of the organic light-emitting diodes (OLEDs) during operation can be attributed to the existence of point defects on the organic layers. In this work, the effect of mixed-host emissive layer and the thermal annealing treatment were investigated to eliminate defects and to boost the device performance. The mixed-host system includes 4,4',4''-tri (9-carbazoyl) triphenylamine (TCTA) and 2,7-bis(diphenylphosphoryl)-9, 9'-spirobi[fluorene] (SPPO13). The mixed-host emissive layer with thermal annealing treatment showed low roughness and few pinholes, and the devices fabricated from this emissive layer exhibited high efficiencies, high stabilities, and long lifetimes. The red and orange-red OLEDs exhibited efficiencies of 13.9 cd/A and 24.35 cd/A, respectively. The longest half-lifetime (L =500 cd/m ) of the red and orange-red OLEDs were 158 h and 180 h, respectively. Efforts were made to solve problems in large-area coating and to reduce the number of defects on in organic layer. Large-active-area (active area=3 cm×4 cm) red phosphorescent OLEDs (PhOLEDs) devices were realized with very high current efficiency up to 9 cd/A.
有机发光二极管（OLED）在运行过程中的不稳定性可归因于有机层上存在点缺陷。在这项工作中，研究了混合主体发光层和热退火处理的效果，以消除缺陷并提高器件性能。混合主体系统包括4,4',4''-三（9-咔唑基）三苯胺（TCTA）和2,7-双（二苯基磷酰基）-9,9'-螺二芴（SPPO13）。经过热退火处理的混合主体发光层显示出低粗糙度和少量针孔，由该发光层制备的器件表现出高效率、高稳定性和长寿命。红色和橙红色OLED的效率分别为13.9 cd/A和24.35 cd/A。红色和橙红色OLED最长的半衰期（L =500 cd/m²）分别为158小时和180小时。人们努力解决大面积涂层中的问题，并减少有机层上的缺陷数量。实现了大面积（有源区=3 cm×4 cm）的红色磷光OLED（PhOLED）器件，其电流效率高达9 cd/A。
