Insight into the growth kinetics of CsPbBr3 perovskite nanocrystals using an oil-water droplet fluidic synthesis route

Abstract

All-inorganic lead halide perovskite nanocrystals (PNCs) have attracted extensive attention in the optoelectronic fields owning to their exceptional photoluminescence characteristics. However, the ultra-fast growth rate of PNCs leads to challenges in controlling their size and optical properties. Here, we report a water–oil droplet fluidic synthesis method that successfully slow down the growth rate of CsPbBr3 PNCs by segregating the cation and anion precursors in the respective phases. Reaction mechanism study revealed a fast nucleation via a nanoplate-intermediate pathway upon HBr diffusion and subsequent slow growth through ripening, leading to a wide range of spectral tunability of the PNCs from 445 nm to 520 nm. The theoretical investigation into growth kinetics showed the combined effect of the ligands and temperature on the growth of the PNCs. This method provides an efficient means for producing high-performance PNCs with tunable size and wavelength while also eliminating the requirement for a Pb-rich reaction environment.