Near Room Temperature Solvothermal Growth of Ferroelectric CsPbBr Nanoplatelets with Ultralow Dark Current.

CsPbBr exhibits outstanding optoelectronic properties and thermal stability, making it a coveted material for detectors, light-emitting diodes, and solar cells. Despite observations of ferroelectricity in CsPbBr quantum dots, synthesizing bulk ferroelectric CsPbBr crystals has remained elusive, hindering its potential in next-generation optoelectronic devices like optical switches and ferroelectric photovoltaics. Here, a breakthrough is reported: a novel solvothermal technique enabling the growth of ferroelectric CsPbBr nanoplatelets with lateral dimensions in the tens of micrometers. This represents a significant step toward achieving large-area ferroelectric CsPbBr crystals. Unlike traditional methods, this approach allows for growth and crystallization of CsPbBr in alcohol solutions by enhancing precursor solubility. This study confirms the ferroelectric nature of these nanoplatelets using second harmonic generation, electrical characterizations, and piezoresponse force microscopy. This work paves the way for utilizing ferroelectric CsPbBr in novel optoelectronic devices, significantly expanding the potential of this material and opening doors for further exploration in this exciting field.