Highly emissive green CsPbBr3/Cs4PbBr6 composites: formation kinetics, excellent heat, light, and polar solvent resistance, and flexible light-emitting application

Benefit from their near-unity photoluminescence quantum yield (PL QY), narrow emission band, and widely tunable bandgap, metal halide perovskites have shown promising in light-emitting applications. Despite such promise, how to facile, environmentally-friendly, and large-scale prepare solid metal halide perovskite with high emission and stability remains a challenging. Herein, we demonstrate a convenient and environmentally-friendly method for the mass synthesis of solid CsPbBr3/Cs4PbBr6 composites using high-power ultrasonication. Adjust-ing key experimental parameters, bright emitting CsPbBr3/Cs4PbBr6 solids with a maximum PL QY of 71% were obtained within 30 min. XRD, SEM, TEM, Abs/PL, XPS, and lifetime characterizations provide solid evidence for forming CsPbBr3/Cs4PbBr6 composites. Taking advantage of these composites, the photostability, thermostability, and polar solvent stability of CsPbBr3/Cs4PbBr6 are much improved compared to CsPbBr3. We further demonstrated CsPbBr3/Cs4PbBr6 use in flexible/stretchable film and high-power WLEDs. After being sub-jected to bending, folding, and twisting, the film retains its bright emission and exhibits good resistance to mechanical deformation. Additionally, our WLEDs display a superior, durable high-power-driving capability, operating currents up to 300 mA and maintaining high luminous intensity for 50 hours. Such highly emissive and stable metal halide perovskites make them promising for solid-state lighting, lasing, and flexible/stretchable display device applications. (c) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

This study demonstrates a convenient and environmentally-friendly method for the mass synthesis of solid metal halide perovskite composites with high emission and stability. The composites exhibit improved photostability, thermostability, and polar solvent stability compared to pure metal halide perovskites. The composites are also successfully applied in flexible/stretchable films and high-power white light-emitting diodes, showing great potential for solid-state lighting, lasing, and flexible/stretchable display device applications.