Room‐Temperature Triple‐Ligand Surface Engineering Synergistically Boosts Ink Stability, Recombination Dynamics, and Charge Injection toward EQE‐11.6% Perovskite QLEDs

• DOI: 10.1002/adma.201800764
• Publication Date: 2018-06-11T06:15:03Z
• Authors: Jizhong Song; Jinhang Li; Leimeng Xu; Jianhai Li; Fengjuan Zhang; Boning Han; Qingsong Shan; Haibo Zeng
• Keywords: Quantum Efficiency; Quantum yield

Developing low-cost and high-quality quantum dots (QDs) or nanocrystals (NCs) their corresponding efficient light-emitting diodes (LEDs) is crucial for the next-generation ultra-high-definition flexible displays. Here, there a report on room-temperature triple-ligand surface engineering strategy to play synergistic role of short ligands tetraoctylammonium bromide (TOAB), didodecyldimethylammonium (DDAB), octanoic acid (OTAc) toward "ideal" perovskite QDs with high photoluminescence yield (PLQY) >90%, unity radiative decay in its intrinsic channel, stable ink characteristics, effective charge injection transportation QD films, resulting highly QD-based LEDs (QLEDs). Furthermore, films less nonradiative recombination centers exhibit improved PL properties PLQY 61% through dopant A-site. The robustness such demonstrated by fabrication green electroluminescent based CsPbBr3 peak external efficiency (EQE) 11.6%, internal (IQE) power are 52.2% 44.65 lm W-1 , respectively, which most-efficient QLEDs colloidal as emitters up now. These results demonstrate that as-obtained inks have wide range application future high-definition displays lightings.