Colloidal Synthesis of CH NH PbBr Nanoplatelets with Polarized Emission through Self-Organization.

We report a combined experimental and theoretical study of the synthesis of CH NH PbBr nanoplatelets through self-organization. Shape transformation from spherical nanodots to square or rectangular nanoplatelets can be achieved by keeping the preformed colloidal nanocrystals at a high concentration (3.5 mg mL ) for 3 days, or combining the synthesis of nanodots with self-organization. The average thickness of the resulting CH NH PbBr nanoplatelets is similar to the size of the original nanoparticles, and we also noticed several nanoplatelets with circular or square holes, suggesting that the shape transformation experienced a self-organization process through dipole-dipole interactions along with a realignment of dipolar vectors. Additionally, the CH NH PbBr nanoplatelets exhibit excellent polarized emissions for stretched CH NH PbBr nanoplatelets embedded in a polymer composite film, showing advantageous photoluminescence properties for display backlights.