Defect-modulated synthesis and optoelectronic properties in chemical vapor deposited CsPbBr3 microplates

The remarkable optoelectronic features of halide perovskite promote their potential applications in semiconductor devices beyond solar cells, which require high-quality single crystals with controlled defect levels. Herein, we investigated the synthesis mechanism of chemical vapor deposited single-crystalline all-inorganic perovskite microplates (MPs), and reported a defect-modulated photocurrent which is closely related to the growth sequence of the MPs. The MP synthesis initiates from island-like nano-disks, and subsequently transits to a layer-by-layer fashion, resulting in a defect-rich area at the center of the MPs. At elevated temperatures, these central defects may be thermally activated and become highly mobile, leading to photoluminescence quenching and degression of local and overall optoelectronic attributes, as evidenced by the spatial resolved optical and electrical scanning probe microscopy. Overall, this work shines light on the formation, proliferation and dynamics of defects in perovskites, and offers guidance for preparation of high-quality perovskites micro-crystals for functional semiconductor devices with high temperature stability.

Automated summary

This study investigated the synthesis mechanism of chemical vapor deposited single-crystalline all-inorganic perovskite microplates and reported a defect-modulated photocurrent related to the growth sequence of the microplates. It was found that the central defects in the microplates may be thermally activated and become highly mobile at elevated temperatures, leading to the degradation of optoelectronic attributes. This work sheds light on the formation, proliferation and dynamics of defects in perovskites, providing guidance for the preparation of high-quality perovskite micro-crystals for functional semiconductor devices with high temperature stability.