Continuous-flow synthesis of doped all-inorganic perovskite nanocrystals enabled by a microfluidic reactor for light-emitting diode application

• Published in: Science China materials 2020-08, Vol.63 (8), p.1526-1536
• Main Authors: Lin, Pengcheng, Chen, Hongbin, Wei, Zhan, Lin, Yingru, Lin, Jinghui, Chen, Ying, Cheng, Zhengdong
• Format: Article
• Language: English
• Subjects: Cerium; Chemistry and Materials Science; Chemistry/Food Science; Color temperature; Continuous flow; Crystal growth; Crystal structure; Doping; Fluorescence; Light emitting diodes; Luminescence; Materials Science; Microchannels; Microfluidics; Nanocrystals; Nucleation; Optical fibers; Optical properties; Optoelectronic devices; Perovskites; Photoluminescence; Quantum efficiency; Stability
• ISSN: 2095-8226; 2199-4501
• DOI: 10.1007/s40843-020-1374-7

All-inorganic perovskite nanocrystals (AIPNCs) possess the advantages of narrow emission spectrum, high quantum efficiency of luminescence and tunable luminescence position, which show abroad application prospect in the fields of optoelectronic materials and devices. Ion doping can tune their pristine crystal structures and luminescent properties or endow the AIPNCs with additional functionalities. Herein, a microfluidic reactor is designed to produce the Ce 3+ -doped AIPNCs based on the continuous-flow reaction. The mechanism of the flow synthesis of Ce 3+ -doped AIPNCs is the efficient physical mixing of the precursor ions in the confined micro-channel, the reaction nucleation of crystal seeds in the poor solvent and the crystal growth of the doped AIPNCs along the flow direction. The synthesis process can be on-line monitored by an optical fiber absorption spectrometer and an optical fiber fluorescence spectrometer. The doping concentration of Ce 3+ can be facilely controlled by changing the flow parameters in the microfluidic reactor, and the highest value reaches 1%. The Ce 3+ doping can improve the photoluminescence efficiency and the stability of the AIPNCs. The Ce 3+ -doped CsPbBr 3 AIPNCs can be used to manufacture green light-emitting diodes (LEDs) with a high color purity of 93.3% and white LEDs with correlated color temperature (CCT) of 10,436 K, CIE color coordinates of (0.261, 0.317) and color-rendering index (CRI) of 72.1. The continuous and controllable synthesis of AIPNCs by microfluidic reactor opens up new avenues for the application of the high-performance optoelectronic materials and devices.