Perovskite nanocrystals: tuneable future for display industry
Perovskite materials have attracted tremendous research interest for its outstanding optoelectronic properties. As a supernova in light-emitting applications, perovskite-based LEDs have reached high efficiencies over 20%  whilst keeping the emission linewidth as narrow as 12 nm . Thanks to its nanocrystal geometry, light emission from lead halide perovskites can be precisely tuned to display different colours; in combination with variable halide composition, perovskite LEDs covered the entire visible spectrum, thus providing opportunities for perovskite-based display for ultra-high definition, flexible, and energy efficient displays.
In this work, a novel engineering platform is developed for synthesizing perovskite nanocrystals. Flow chemistry has been widely applied as a versatile tool for nanoparticle synthesis, and this engineering concept brings opportunity for controlled growth for perovskite without changing the chemistry. With the help of helical coiled microreactor, perovskite nanocrystals have been synthesized as quantum dots, which exhibited strong quantum confinement effect. By altering the flow characteristics in the reactor, emission from CsPbBr3 quantum dots can be finely tuned towards blue from green which is observed in CsPbBr3 crystalline thin films. This marks a leap towards fully perovskite-based displays.
 K. Lin, J. Xing, L. N. Quan, F. P. G. de Arquer, X. Gong, J. Lu, L. Xie, W. Zhao, D. Zhang, C. Yan, W. Li, X. Liu, Y. Lu, J. Kirman, E. H. Sargent, Q. Xiong, Z. Wei, Nature 2018, 562, 245.
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