Defect step controlled growth of perovskite MAPbBr3 single crystal

Perovskite MAPbBr 3 (MA = CH 3 NH 3 + ) single crystals were grown via the anti-solvent vapor-assisted crystallization method. The crystal growth process was optimized by adjusting the solution concentration and diluting the anti-solvent. The maximum size of the obtained crystal was 9 × 9 × 3 mm 3 . It shows that the MAPbBr 3 single crystal is a cubic structure, the space group is Pm \( \bar{3} \) m , and the lattice constant is 0.59062 nm. Furthermore, its energy band gap is approximately 2.23 eV. The atomic force microscopy results demonstrated that the growth process of MAPbBr 3 single crystal followed the defect step growth mechanism, which was controlled by the screw dislocations within the crystal. Based on the curling growth of a screw dislocation on the crystal surface, a spiral step was formed. After the step was rotated around the entire mesa, a higher step was generated. Repeatedly, the step growth of screw dislocation within the crystal came into being. Besides, some small pits were also observed on (100) plane of the MAPbBr 3 crystal. These pits hindered the movement of steps and affected the lattice arrangement around them, causing the structural mismatch and more defects within the crystals.