Highly efficient, solution processed electrofluorescent small molecule white organic light-emitting diodes with a hybrid electron injection layer.
Highly efficient, solution-processed, and all fluorescent white organic light-emitting diodes (WOLEDs) based on fluorescent small molecules have been achieved by incorporating a low-conductivity hole injection layer and an inorganic-organic hybrid electron injection layer. The light-emission layer is created by doping a fluorescent π-conjugated blue dendrimer host (the zeroth generation dendrimer, G0) with a yellow-emitting fluorescent dopant oligo(paraphenylenevinylene) derivative CN-DPASDB with a doping ratio of 100:0.15 (G0:CN-DPASDB) by weight. To suppress excessive holes, the high-conductivity hole injection layer (PEDOT:PSS AI 4083) is replaced by the low-conductivity PEDOT:PSS CH 8000. To facilitate the electron injection, a hybrid electron injection layer is introduced by doping a methanol/water-soluble conjugated polymer poly[(9,9-bis(30-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFNR2) with solution-processed cesium fluoride (CsF). The device achieves a maximum luminous efficiency of 17.0 cd A(-1) and a peak power efficiency of 15.6 lm W(-1) at (0.32, 0.37) with a color rendering index of 64.
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.
Zhixiong
Z
Jiang
Zhiming
Z
Zhong
Shanfeng
S
Xue
Yan
Y
Zhou
Yanhong
Y
Meng
Zhanhao
Z
Hu
Na
N
Ai
Jianbin
J
Wang
Lei
L
Wang
Junbiao
J
Peng
Yuguang
Y
Ma
Jian
J
Pei
Jian
J
Wang
Yong
Y
Cao