Improvement in optical properties of CsPbBr nanocrystals using aprotic polar purification solvent.

We demonstrate the influence mechanism on the optical property of CsPbBr during purification of solution with different protonated levels and polarities. During the purification process, organic groups originating from oleic acid (OA) and PbBr impurity on the surface of CsPbBr nanocrystals can be removed using high polarity aprotic and protonic solvents, and the number of Br vacancies ( ) can be reduced. The protonic polar solvent can not only etch the organic groups on the surface of nanocrystals, causing surface reconstruction and particle growth of nanocrystals, but also enter into the lattice of CsPbBr and react with the embedded CsPbBr.

Ligand and adjuvant dual-assisted synthesis of highly luminescent and stable CsPbBr nanoparticles used in LEDs.

We developed a new ligand and adjuvant dual-assisted room temperature colloidal method for the synthesis of highly luminescent and stable CsPbBr nanoparticles, in which acetone, oleamine (OM) and oleic acid (OA) were used as precursors, while water and dimethyl sulfoxide (DMSO) were used as adjuvants. In this process, we explored the influencing factors of process parameters (such as the amount of water, the standing time of precursors, and the molar ratio of raw materials), and found that CsPbBr synthesized by water + DMSO can not only change the morphology and promote crystallization but also improve the lattice strain, reduce the lattice defects and optimize the passivation effect, so as to improve the luminescence properties. Simultaneously, we also found that the pc-LED made of CsPbBr can still emit bright green light after 4344 h of operation, showing excellent stability and making it promising for solid-state lighting application.