Fig. 1. （a） Schematic growth of MAPbBr₃ crystal and photographs of crystals grown with/without additives； （b） XRD patterns of MAPbBr₃ single crystals grown with/without additives

Fig. 2. High-resolution XRD rocking curves of grown crystal （001） plane with （a） / without （b） additives

Fig. 3. Schematic diagram of surface growth and defect passivation mechanism of perovskite single crystal

Fig. 4. Contact angle of water solution on the surface of grown single crystals with （a） /without （b） additive

Fig. 5. FT-IR spectra （a） and XPS measurement result （b） of crystal grown with/without additive， and XPS of Pb 4f （c） and Br 3p （d）

Fig. 6. （a） Photograph of device； （b） I-V curves of crystal devices grown with/without additives； light-dark current curves （c） and carrier mobility lifetime product （d） of crystal devices grown with/without additives

Fig. 7. （a） Attenuation efficiency to 50 kV X-ray photons versus thickness of MAbBr₃； J-t response of the grown crystal devices with （b）/without （c） additives under different biases； sensitivity of the grown crystal devices with （d） / without （e） additives under different biases； （f） I-t curves of the light-dark currents of the grown crystal devices with/without additives at a test period of 1 000 s