Stable and highly efficient blue-emitting CsPbBr3 perovskite nanomaterials via kinetic-controlled growth

Compared to the classical II-VI quantum dots (QDs), the reaction kinetics of cesium lead halide perovskite nanocrystals (NCs) are not clear yet because of the fast reaction rate. Here, an Ag+-assisted slow-release strategy is proposed to synthesize CsPbBr3 nanomaterials, where the reaction rate is decreased and the reaction time is prolonged to days. It is found that the Ag+ ions can bind with the PbBr2 precursor, which makes the formation of PbBr64- as the rate-limiting step. Shape conversion from dots to nanowires and then to platelets has been observed for the CsPbBr3. Pure blue-emitting nanoplatelets (NPLs) with near unity photoluminescence quantum yield (QY) are acquired. In addition, the blue-emitting CsPbBr3 solution is very stable, which has been stored for over 1.5 years without performance degradation. A liquid light-emitting diode (LED) prototype is further fabricated and exhibits excellent stability towards driving currents.

Automated summary

A strategy utilizing Ag+ for slow-release was proposed to synthesize CsPbBr3 nanomaterials, leading to shape conversion from dots to nanowires and eventually to platelets. The nanoscale platelets exhibited near unity photoluminescence quantum yield and high stability in blue-emitting CsPbBr3 solution. Additionally, a liquid LED prototype fabricated showed excellent stability towards driving currents.