Carrier dynamics in CsPbI_3 perovskite microcrystals synthesized in solution phase

摘要

All-inorganic cesium lead halide perovskites(CsPbX_3, X = Cl^-,Br^-, I^-) could provide comparable optoelectronic properties as a promising class of materials for photovoltaic cell(PV), photodetector and light-emitting diode(LED) with enhanced thermal and moisture stabilities compared to organicinorganic lead halide species. However, fabrication of CsPbI_3 perovskite via facile solution process has been difficult due to instability of CsPbI_3 in the perovskite cubic phase in ambient air. Herein, we report the synthesis of CsPbI_3 perovskite microcrystals by low-temperature, catalyst-free, solution-phase method. By applying the time-resolve spectroscopic technique, we determine the carrier diffusion coefficient of 0.6–1.2 cm^2/s, the intrinsic carrier lifetimes of 200–1300 ns and diffusion length of 4–10μm in different individual CsPbI_3 perovskite microcrystals. Our results suggest the CsPbI_3 perovskite microcrystals synthesized by solution process exhibit high quality feature and are suitable for applications in optoelectronic devices.