Single Crystal Perovskite MAPbBr₃Prepared by Using Anti-solvent Vapor-assisted Crystallization Method

Perovskite methylammonium lead tri-bromide (MAPbBr3) material has gained a lot of attention in the past few years due to its impressive optoelectronic properties, which is suitable for high efficiency and sensitivity X-ray photodetector. Compared to polycrystalline crystal structure, MAPbBr3 single crystal is more ideal for X-ray photodetector because lack of grain boundary therefore produce more sensitive photodetector. However, a cubic structure and large crystal dimension is highly required to adjust into the flat-panel detector configuration. In this research, MAPbBr3 perovskite crystals were synthesized by using Anti-solvent Vapor-assisted Crystallization (AVC) at room temperature using dimethylformamide (DMF) as solvent and Dichloromethane (DCM) as antisolvent. The precursors for the MAPbBr3 solution were prepared by varying the molar ratio of MABr:PbBr2 as precursor solution. The crystal growth rate was controlled by varying the volume ratio of DCM and MAPbBr3 precursor solution. The obtained largest crystal size of 10 mm × 10 mm was prepared with a volume ratio of DCM and precursor is 3 and a volume of precursor solution is 6 ml. The XRD of large cubic MAPbBr3 crystal showed a peak of (100) plane, which indicates a single crystal oriented in a-axis direction. The Raman spectra peaks of perovskite MAPbBr3 crystals showed organic (MA+) and inorganic (PbBr2-) bonds in a cubic phase of single crystal MAPbBr3. All samples that were prepared with different ratios of DCM and precursor solution have the same Raman spectra, which confirm that all MAPbBr3 crystals have cubic crystal structure.