Engineering CsPbBr3 perovskite from 2D nanoplatelets to 0D quantum dots via polar solvent post-treatment

Cesium lead halide (CsPbX 3 X = I, Br, Cl) perovskites have potential applications in the fields of X-ray fluorescence imaging, solar cells, light-emitting diodes (LEDs) and photocatalysis due to their excellent optical and electrical properties. In this work, we propose a novel method to tune the emission color of CsPbBr 3 by polar solvent post-treatment. The blue emission color of the two-dimensional (2D) CsPbBr 3 nanoplatelets (NPLs) prepared at room temperature is evidently changed to green under UV excitation via DMF post-treatment. We verify the DMF is used to decompose these NPLs into 0D quantum dots followed by the color variation. We further reveals the polarity of the employed solvent is the main parameter in the decomposition processes. This novel route might be suitable for other 2D perovskites and benefit the application of these colorful products in LEDs and information storage fields.