Formation of CsPbCl<sub>3</sub> Cubes and Edge-Truncated Cuboids at Room Temperature
Yun-Wen Peng, Chia-Peng Wang, Gautam Kumar, Pei‐Lun Hsieh, Chia‐Min Hsieh, Michael H. Huang
Abstract
In contrast to the normal formation of cubic metal halide perovskite nanocrystals, CsPbCl3 cubes and edge-truncated cuboids have been synthesized by simply mixing CsCl, PbCl2, and sodium dodecyl sulfate (SDS) in dimethyl sulfoxide (DMSO) at room temperature and transferring a small volume of the mixture to toluene to form a precipitate. The tetragonal-phased CsPbCl3 cubes and some rectangular blocks have square and rectangular {100}/{001} faces, while the cuboids have additional {101}/{110} edges. Variation in the amount of PbCl2 transforms cubes to edge-truncated cuboids. Their absorption and emission band positions are nearly identical at 413–416 nm. Despite having relatively large sizes, the CsPbCl3 cubes and edge-truncated cuboids display photoluminescence quantum yields of 6.9 and 2.9%, respectively. Remarkably, adding didecyldimethylammonium chloride (DDAC) surfactant to the reaction mixture leads to a 2–4.6-fold enhancement in the emission intensity. It is envisioned that other cesium lead halide crystals of tunable shapes can be synthesized by using the green reaction conditions.