This invention uses ultrasonication to create a burst of nucleation to overcome the activation barriers of LHPs crystallization and produces high-quality micro- and sub-micron LHPs crystals and dual-phase LHPs nanocrystals in non-perovskite matrices. The process is well suited for the rapid and large-scale fabrication of LHP microcrystals (e.g. 10 billion particles/L). LHPs crystallization is facilitated by several minutes of ultrasonication at room temperature using a bath- or tip-type ultrasonicator. The reaction is completed within 2-15 mins. Single- and dual-phase microparticles with a variety of morphologies can be generated depending on the amount of precursors, their concentration ratios, and the presence of non-ionic surfactants. The ultrasonication method can improve the luminescent properties and structural stability of LHP microcrystals by enabling in-situ coating with polar prepolymers like pNE. Coating with polar prepolymers then enables the functionalization LHPs particles with various polar materials, including plasmonic nanoparticles.