Solvent-Free Mechanosynthesis of Composition-Tunable Cesium Lead Halide Perovskite Quantum Dots

A facile and green mechanosynthesis strategy free of solvent and high reaction temperature was developed to fabricate highly emissive cesium lead halide perovskite (CsPbX₃) quantum dots (QDs). Their composition can be adjusted conveniently simply through mechanically milling/grinding stoichiometric combinations of raw reagents, thereby introducing a broad luminescence tunability of the product with adjustable wavelength, line width, and photoluminescence quantum yield. Desired CsPbX₃ QDs "library" can thus be readily constructed in a way like assembling Lego building blocks. Hence, the method offered new avenues in the preparation of multicomponent cocrystals, adding one appealing apparatus to the tool box of perovskite-type QDs synthesis. Intriguingly, photoinduced dynamic study revealed the hole-transfer process of the as-prepared QDs toward electron donors, indicative of their potential in charge-transfer-based applications such as light-harvesting devices and photocatalysis.