Mechanism of the surface-preferred crystal plane of CsPbBr3 single crystals in different solvents

CsPbBr3 single crystals have been grown by using solution method with hydrobromic acid (HBr) and dimethyl sulfoxide (DMSO), respectively. The same orthorhombic phase of crystals grown in these two solvents was confirmed by X-ray powder diffraction (XRD). A very interesting phenomenon is that the surface-preferred crystal plane of the CsPbBr3 single crystal would be (2 0 0) in HBr solution, while that would be (1 0 1) in DMSO solution. Remarkably, this growth mechanism can be explained effectively by the principle of opposite charges attraction, which would be likely to provide an approach to be extended to the regulation of surface-preferred crystal plane of other perovskite single crystals grown in different solvents, especially using solvent with original perovskite solute ions.