A CTAB-mediated antisolvent vapor route to shale-like Cs 4 PbBr 6 microplates showing an eminent photoluminescence.

Compared with nanoscale quantum dots (QDs), the large-sized perovskite crystals not only possess better stability but also are convenient for application exploration. Herein, we develop a facile and efficient antisolvent vapor-assisted recrystallization approach for the synthesis of large-sized Cs 4 PbBr 6 perovskite crystal microplates. In this method, for the first time, the shale-like Cs 4 PbBr 6 microplates with lateral dimensions of hundreds of microns are fabricated by employing cetyltriethylammnonium bromide (CTAB) as a morphology-directing agent. FESEM, TEM, and AFM characterizations indicate that the as-obtained shale-like Cs 4 PbBr 6 microplates are actually formed by 6-8 nm thick Cs 4 PbBr 6 nanosheets with orientational stacking. Importantly, such highly crystalline Cs 4 PbBr 6 microplates with shale-like morphology exhibit a narrow and intense green PL emission with a 59% PL quantum yield. Moreover, the planar structure of shale-like Cs 4 PbBr 6 microplates makes it easy to form a preferred orientation on a substrate, which endow them with promising potential in optoelectronic devices such as lighting and displays.