Growth and Self-Assembly of CsPbBr Nanocrystals in the TOPO/PbBr Synthesis as Seen with X-ray Scattering.

Despite broad interest in colloidal lead halide perovskite nanocrystals (LHP NCs), their intrinsic fast growth has prevented controlled synthesis of small, monodisperse crystals and insights into the reaction mechanism. Recently, a much slower synthesis of LHP NCs with extreme size control has been reported, based on diluted TOPO/PbBr precursors and a diisooctylphosphinate capping ligand. We report new insights into the nucleation, growth, and self-assembly in this reaction, obtained by synchrotron-based small-angle X-ray scattering and optical absorption spectroscopy.