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

CsPbBr3 emerges as a representative inorganic perovskite due to its feasible synthesis and outstanding properties. In this work, high-quality orthorhombic and cubic CsPbBr3 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 CsPbBr3 has a larger averaged carrier lifetime than those of the orthorhombic CsPbBr3 crystal, extremely asymmetry in the I-V curves and abnormal hysteresis behaviors are observed in cubic CsPbBr3, and an overshoot followed by a slow decay in the photocurrent becomes more pronounced in cubic CsPbBr3 as light illumination intensity increases, reflecting the significant effect of ion migration in the photoelectric performance in cubic CsPbBr3. On the other hand, the photocurrent in orthorhombic CsPbBr3 exhibits excellent response ability and stability, showing a large light-to-dark ratio of 15.2, roughly 7 times larger than cubic CsPbBr3. The differences in the photoelectrical properties between cubic and orthorhombic CsPbBr3 provide insights into the influence of crystal structure on the photoelectronic properties of perovskite materials.

Automated summary

In this study, high-quality orthorhombic and cubic CsPbBr3 single crystals were successfully grown, and the correlation between the photoelectrical properties and crystal structures was investigated. It was found that even though cubic CsPbBr3 has a longer carrier lifetime, hysteresis behaviors and overshoot in the photocurrent were observed as the light illumination intensity increased, while orthorhombic CsPbBr3 exhibited excellent response ability and stability.