Capping Ligand Engineering Enables Stable CsPbBr<sub>3</sub> Perovskite Quantum Dots toward White-Light-Emitting Diodes
Xiaolin Zhu, Zhangcheng Pan, Tianyue Xu, Xiuwen Shao, Zhaoju Gao, Qingyu Xie, Yupeng Ying, Wei Pei, Hao Lin, Jia Wang, Xiaosheng Tang, Wei Wei Chen, Yongfeng Liu
Abstract
All-inorganic perovskite quantum dots (PeQDs) have sparked extensive research focus on white-light-emitting diodes (WLEDs), but stability and photoluminescence efficiency issues are still remain obstacles impeding their practical application. Here, we reported a facile one-step method to synthesize CsPbBr 3 PeQDs at room temperature using branched didodecyldimethylammonium fluoride (DDAF) and short-chain-length octanoic acid as capping ligands. The obtained CsPbBr 3 PeQDs have a near-unity photoluminescence quantum yield of 97% due to the effective passivation of DDAF. More importantly, they exhibit much improved stability against air, heat, and polar solvents, maintaining >70% of initial PL intensity. Making use of these excellent optoelectronic properties, WLEDs based on CsPbBr 3 PeQDs, CsPbBr 1.2 I 1.8 PeQDs, and blue LEDs were fabricated, which show a color gamut of 122.7% of the National Television System Committee standard, a luminous efficacy of 17.1 lm/W, with a color temperature of 5890 K, and CIE coordinates of (0.32, 0.35). These results indicate that the CsPbBr 3 PeQDs have great practical potential in wide-color-gamut displays.