In Situ Synthesis of Ultrastable CsPbBr₃ Perovskite Nanocrystals Coated with Polyimide in a CSTR System

The poor stability of perovskite nanocrystals (NCs) is one of the major obstacles for their application in optoelectronic devices. Herein, we develop an easy in situ strategy for preparing polyimide (PI)-coated single-particle CsPbBr₃ NCs in a continuous stirred-tank reactor system. Benefiting from the protection of the thick polyimide layer, these PI-coated CsPbBr₃ NCs show excellent stability against severe environments such as water, heat, oxygen, and light. Meanwhile, time-resolved photoluminescence and ultrafast transient absorption spectroscopy revealed that the polyimide (PI) polymer contributes to passivating the surface defects of the CsPbBr₃ NCs, giving CsPbBr₃/PI NCs a higher photoluminescence quantum yield. Thanks to the performances of high luminescent efficiency and stability, these green-emitting perovskite CsPbBr₃/PI NCs show promising potentials in the fields of solid-state lighting and display.