State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry , University of Chinese Academy of Sciences , Changchun 130022 , P. R. China.
Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , P. R. China.
ACS Appl Mater Interfaces. 2018 Mar 7;10(9):8148-8154. doi: 10.1021/acsami.8b00513. Epub 2018 Feb 27.
Phosphorescent organic light-emitting diodes (OLEDs) possess the property of high efficiency but have serious efficiency roll-off at high luminance. Herein, we manufactured high-efficiency phosphorescent OLEDs with extremely low roll-off by effectively locating the ultrathin emitting layer (UEML) away from the high-concentration exciton formation region. The strategic exciton management in this simple UEML architecture greatly suppressed the exciton annihilation due to the expansion of the exciton diffusion region; thus, this efficiency roll-off at high luminance was significantly improved. The resulting green phosphorescent OLEDs exhibited the maximum external quantum efficiency of 25.5%, current efficiency of 98.0 cd A, and power efficiency of 85.4 lm W and still had 25.1%, 94.9 cd A, and 55.5 lm W at 5000 cd m luminance, and retained 24.3%, 92.7 cd A, and 49.3 lm W at 10 000 cd m luminance, respectively. Compared with the usual structures, the improvement demonstrated in this work displays potential value in applications.
磷光有机发光二极管（OLED）具有高效率的特性，但在高亮度下效率会严重下降。在此，我们通过将超薄发光层（UEML）有效地定位在高浓度激子形成区域之外，制造出具有极低效率下降的高效磷光 OLED。在这种简单的 UEML 结构中，策略性的激子管理极大地抑制了由于激子扩散区域扩大而导致的激子猝灭，从而显著改善了高亮度下的效率下降。所得的绿色磷光 OLED 的最大外量子效率为 25.5%，电流效率为 98.0 cd A，功率效率为 85.4 lm W，在 5000 cd m 亮度下仍保持 25.1%、94.9 cd A 和 55.5 lm W，在 10000 cd m 亮度下仍保持 24.3%、92.7 cd A 和 49.3 lm W。与通常的结构相比，本工作的改进在应用中具有潜在的价值。
