Elimination of unexpected destruction on CsPbBrxI3-x nanocrystals arising from polymer matrix.

Cesium lead halide perovskite (CsPbX 3) nanocrystals (NCs) have exhibited promising applications in light-emitting diodes (LEDs) due to their tunable bandgap and high quantum efficiency. Backlighting LEDs based on CsPbBr 3 NCs with green emission have been widely designed to show their superiority. However, unlike CsPbBr 3 NCs, backlighting LEDs composed of mixed-halide perovskite (CsPbBr x I 3-x) NCs have rarely been reported and should be further applied in colorful LEDs for granted, mainly because of the unexpected destructive effects from the commercial polymer matrix verified in this work. Purification of a commercial polymer matrix was promoted as an effective method to eliminate the destructive effects. Further investigation proved that the species with strong polarity and oxidability, e.g., BPO in commercial PMMA, are responsible for such destructive effects by inducing the structural transformation of CsPbBr x I 3-x NCs. We believe such results can help to gain a deeper understanding of the degradation mechanism of mixed-halide perovskite materials and indicate a promising method to develop stable colorful perovskite-based LEDs. • Commercial polymer matrix have unexpected destructive effects on CsPbBr x I 3-x NCs. • Destructive effects were from the synergistic effect between polar species in commercial polymer matrix and CsPbBr x I 3-x NCs. • Purification of the commercial polymer matrix can be an effective method to eliminate the destructive effects. • CsPbBr x I 3-x NCs embedded in purified PMMA can exhibit superior stability in both solution and film. [ABSTRACT FROM AUTHOR]