1. 47-Fold EQE improvement in CsPbBr3 perovskite light-emitting diodes via double-additives assistance
- Author
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Xing-Juan Ma, Zu-Hong Xiong, Run Wang, Ya-Lan Jia, Fu-Xing Yu, Zi-Yang Xiong, Yajie Dong, Chun-Hong Gao, Yue Zhang, Dong-Ying Zhou, and Ping Chen
- Subjects
Materials science ,Passivation ,Exciton ,02 engineering and technology ,Electroluminescence ,010402 general chemistry ,01 natural sciences ,law.invention ,Biomaterials ,law ,Materials Chemistry ,Electrical and Electronic Engineering ,Diode ,business.industry ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Optoelectronics ,Quantum efficiency ,Charge carrier ,0210 nano-technology ,business ,Phosphorescence ,Light-emitting diode - Abstract
All-inorganic cesium halide perovskite materials are intensively investigated due to their excellent photoelectric characteristics, but poor film coverage, unbalanced charge carrier transporting and insufficient exciton harvesting are remaining challenges to be overcome in order to achieve high electroluminescent (EL) performance in perovskite light-emitting diodes (PeLEDs). Here we show that these problems can be solved by introducing both a phosphorescent sensitizer (FIrpic) and an electron transporting material (TmPyPB) into all-inorganic cesium halide perovskite (CsPbBr3). And highly efficient green PeLEDs with full coverage CsPbBr3:TmPyPB:FIrpic film as the emissive layer have been achieved, exhibiting the maximum luminance of 37784 cd/m2, the maximum current efficiency of 22.6 cd/A and the corresponding maximum external quantum efficiency (EQE) of 5.85%, where the EQE is 48-fold to that of bare CsPbBr3 PeLEDs. The enhanced EL performance is attributed to less non-radiative current leakage, better film surface passivation effect, balanced charge carrier injection and transportation, as well as better exciton harvesting. It is believed that our work will provide an effective strategy to further improve EL performance of PeLEDs via better exciton harvesting.
- Published
- 2019