Kinetic study on growth of organic lead halide perovskite nanocrystals through water-oil interfacial reaction

Formation of organometal lead halide perovskite nanocrystals (OPNCs) occurs in fast time scales from milli-seconds to seconds, thus posing a hurdle to the growth kinetic study of OPNCs. Water-oil interfacial reaction provides an effective approach for retarding the growth of CH3NH3PbBr3 OPNCs. Herein, we investigate sys-tematically the kinetics of CH3NH3PbBr3 NCs in water-oil reaction by in situ optical characterization, and identify the key factors governing the growth of OPNCs. Molecular polarity and viscosity of the solvent are found to be crucial to the diffusion step by affecting the diffusion coefficient of CH3NH3+. Covalent characteristic of the Pb source and molecular structure of the ligands have an impact on the rate-limiting step of PbBr64-formation. In addition, we establish the reaction condition that enables controlled growth of formamidinium lead bromide NCs, thereby demonstrating the application of the growth kinetic in the synthesis of other OPNCs. Kinetic investigation of OPNCs provides a better understanding of their crystallization process that helps guide the development of quantum confined OPNCs for optoelectronic applications.