Growth, characterization and photoelectrical properties of orthorhombic and cubic CsPbBr3 single crystals

CsPbBr 3 emerges as a representative inorganic perovskite due to its feasible synthesis and outstanding properties. In this work, high-quality orthorhombic and cubic CsPbBr 3 single crystals (SCs) are successfully grown by a modified inverse temperature crystallization method. Current–voltage ( I – V ) and current–time ( I – t ) curves were systematically measured under various biases and light illumination intensities to investigate the correlation between the photoelectrical properties and the crystal structures. Even though the cubic CsPbBr 3 has a larger averaged carrier lifetime than those of the orthorhombic CsPbBr 3 crystal, extremely asymmetry in the I–V curves and abnormal hysteresis behaviors are observed in cubic CsPbBr 3 , and an overshoot followed by a slow decay in the photocurrent becomes more pronounced in cubic CsPbBr 3 as light illumination intensity increases, reflecting the significant effect of ion migration in the photoelectric performance in cubic CsPbBr 3 . On the other hand, the photocurrent in orthorhombic CsPbBr 3 exhibits excellent response ability and stability, showing a large light-to-dark ratio of 15.2, roughly 7 times larger than cubic CsPbBr 3 . The differences in the photoelectrical properties between cubic and orthorhombic CsPbBr 3 provide insights into the influence of crystal structure on the photoelectronic properties of perovskite materials.