Highly Emissive Green Perovskite Nanocrystals in a Solid State Crystalline Matrix.

Perovskite nanocrystals (NCs) have attracted attention due to their high photoluminescence quantum yield (PLQY) in solution; however, maintaining high emission efficiency in the solid state remains a challenge. This study presents a solution-phase synthesis of efficient green-emitting perovskite NCs (CsPbBr3 ) embedded in robust and air-stable rhombic prism hexabromide (Cs4 PbBr6 ) microcrystals, reaching a PLQY of 90%. Theoretical modeling and experimental characterization suggest that lattice matching between the NCs and the matrix contribute to improved passivation, while spatial confinement enhances the radiative rate of the NCs. In addition, dispersing the NCs in a matrix prevents agglomeration, which explains their high PLQY.