Large-Size CH₃NH₃PbBr₃ Single Crystal: Growth and In Situ Characterization of the Photophysics Properties

We reported a facile single-solution fabrication method to grow large-scale CH₃NH₃PbBr₃ hybrid perovskite single crystal at room temperature. The obtained single crystal in this experiment was 14 × 14 mm. The sample’s in situ photophysics properties under dark and illumination, including the surface morphology, work function, surface current distribution, microcosmic I–V curves, as well as the polarization behavior, were in situ characterized by integrated utilization of a scanning probe microscopy, respectively. Piezoresponse force microscopy (PFM) phase angles indicated the existence of “polarization” in CH₃NH₃PbBr₃ lattice. Interestingly, the “polarization effect” was enhanced by the plus light source. Moreover, a surface potential shift as large as 200 mV was observed under the condition of the illumination on and off. This research is proposed to provide an opportunity to take a fresh look at the architectural design and photovoltaic performance origin of the hybrid perovskite solar cells.