School of Advanced Materials, Peking University Shenzhen Graduate School, Peking University , Shenzhen 518055, China.
Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , Suzhou, Jiangsu 215123, China.
ACS Appl Mater Interfaces. 2017 Jan 25;9(3):2701-2710. doi: 10.1021/acsami.6b13077. Epub 2017 Jan 12.
A novel exciplex-forming host is applied so as to design highly simplified reddish orange light-emitting diodes (OLEDs) with low driving voltage, high efficiency, and an extraordinarily low efficiency roll-off, by combining N,N-10-triphenyl-10H-spiro [acridine-9,9'-fluoren]-3'-amine (SAFDPA) with 4,7-diphenyl-1,10-phenanthroline (Bphen) doped with trivalent iridium complex bis(2-methyldibenzo[f,h]quinoxaline) (acetylacetonate)iridium(III) (Ir(MDQ)(acac)). The reddish orange OLEDs achieve a strikingly high power efficiency (PE) of 31.80 lm/W with an ultralow threshold voltage of 2.24 V which is almost equal to the triplet energy level of the phosphorescent reddish orange emitting dopant. The power efficiency of the device with the exciplex-forming host is enhanced, achieving 36.2% mainly owing to the lower operating voltage by the novel exciplex forming cohost, compared with the reference device (23.54 lm/W). Moreover, the OLEDs show extraordinarily low current efficiency (CE) roll-off to 1.41% at the brightness from 500 to 5000 cd/m with a maximal CE of 32.87 cd/A (EQE = 11.01%). The devices display a good reddish orange color (CIE of (0.628, 0.372) at 500 cd/m) nearly without color shift with increasing brightness. Co-host architecture phosphorescent OLEDs show a simpler device structure, lower working voltage, and a better efficiency and stability than those of the reference devices without the cohost architecture, which helps to simplify the OLED structure, lower the cost, and popularize OLED technology.
一种新型激基复合物形成主体被应用于设计具有低驱动电压、高效率和极低效率滚降的高度简化的橙红色发光二极管（OLED），通过将 N,N-10-三苯基-10H-螺[吖啶-9,9'-菲]-3'-胺（SAFDPA）与 4,7-二苯基-1,10-菲咯啉（Bphen）掺杂三价铱配合物双（2-甲基二苯并[f,h]喹喔啉）（乙酰丙酮）铱（III）（Ir（MDQ）（acac））结合。橙红色 OLED 实现了高达 31.80 lm/W 的显著高功率效率（PE），超低的阈值电压为 2.24 V，几乎等于磷光橙红色发射掺杂剂的三重态能级。具有激基复合物形成主体的器件的功率效率得到增强，主要归因于新型激基复合物形成共主体的较低工作电压，与参考器件（23.54 lm/W）相比，效率提高了 36.2%。此外，OLED 在从 500 到 5000 cd/m 的亮度下显示出极低的电流效率（CE）滚降，最大 CE 为 32.87 cd/A（EQE = 11.01%），在亮度为 5000 cd/m 时 CE 仍为 1.41%。这些器件显示出良好的橙红色颜色（在 500 cd/m 时 CIE 为（0.628，0.372）），几乎没有随着亮度的增加而发生颜色偏移。共主体架构磷光 OLED 与没有共主体架构的参考器件相比，具有更简单的器件结构、更低的工作电压以及更好的效率和稳定性，这有助于简化 OLED 结构、降低成本和推广 OLED 技术。
