Stable green and red dual-color emission in all-inorganic halide-mixed perovskite single microsheets

Recently, all-inorganic perovskites have attracted tremendous attention due to their excellent optoelectronic properties and extensive potential applications. However, these perovskites usually show a single emission wavelength because of the high ionic migration. Herein, we synthesized all-inorganic halide-mixed perovskite CsPbBr I_3- microsheets with high crystal quality using the anti-solvent solution method and observed extraordinary green and red dual-color emission in single CsPbBr I_3- microsheets. Power dependent PL spectra reveal excitonic and defect related recombination features of CsPbBr₃ and CsPbI₃ for the green and red emission. Temperature dependent PL spectra indicated a distinctive exciton-phonon coupling strength in CsPbBr I_3- microsheets compared with pure CsPbBr₃ and CsPbI₃. The PL dynamics showing longer emission lifetime further confirmed this conclusion. Our work not only provides a novel strategy to produce stable dual-color emission integration, but also promotes the fundamental insight into the emission dynamics and exciton/free carrier related photophysics in all-inorganic halide-mixed perovskites.