Zirconium Phosphate-Directed Matrix-Assisted Re-Precipitation (MARP) of Perovskites for Phase Engineering and Stability

A novel “matrix assisted reprecipitation” (MARP) strategy is introduced employing exfoliated zirconium phosphate (Exf-ZrP) inorganic matrix to direct perovskite (Cs₄PbBr₆-CsPbBr₃) crystallization and enable post-synthetic phase engineering. A sub-1 wt.% loading of the Exf-ZrP matrix not only boosts the photoluminescence quantum yield (PLQY) of the perovskite to 75%, a 2.4-fold enhancement over the matrix-free, conventional, ligand-assisted reprecipitation (LARP) method-but also promotes the formation of larger CsPbBr₃ domains (up to 45 nm) within the Cs₄PbBr₆ host, resulting in a red shifted emission at 520 nm and significantly improves perovskite dispersibility. The Exf-ZrP matrix also directs a water-induced solid-state phase conversion of Cs₄PbBr₆ into CsPbBr₃, resulting in enhanced photoluminescence (PL) with additional red shift upto 530 nm, characteristic of high-purity green wavelength suitable for display technologies. Moreover, MARP perovskites exhibit enhanced thermal and photostability compared to LARP perovskites. The results demonstrate a new paradigm for nanoengineered perovskite systems with on-demand optical properties and stability, expanding their functional scope in emerging material platforms.