Here, we present a single atomic supersaturated recrystallization method to synthesize the green-emitting CsPbBr3-Cs4PbBr6 perovskite composites in solid state with the highest PLQY of 40.8% in pure polar solvent. The component, morphology, and optical properties of the microcrystals can be tuned by varying growth time, the content of ammonium bromide, and bromine source. The developed method provides a new route to large-scale synthesize high quality perovskite composites emitters for light-emitting diodes. (C) 2018 Elsevier Inc. All rights reserved.