Air-Stable Lead-Free Perovskite Thin Film Based on CsBi3I10 and Its Application in Resistive Switching Devices.

The development of organic-inorganic hybrid perovskite materials has been rapid in recent years; but their applications are limited by the toxicity and stability of the materials. To address these issues in the context of resistive switching devices, an inorganic lead-free perovskite namely CsBi3I10 is developed. Uniform and pinhole-free CsBi3I10 thin films can be fabricated by using CsI-rich precursor solution via a facile antisolvent-assisted spin-coating method. The nonvolatile resistive switching devices based on CsBi3I10 demonstrate a large on/off ratio (103), reliable retention properties (104 s), and endurance (150 cycles). Conductive atomic force microscopy reveals that the high- and low-resistance states are formed by breaking and formation of conductive filaments in the perovskite thin film. Because of the excellent stability of the CsBi3I10 perovskite, the devices exhibit no obvious change in resistive switching behavior even after over 2 month storage in an ambient (60% relative humidity) environment. Our work suggests that the all-inorganic lead-free CsBi3I10 perovskite has great potential in resistive switching memory as well as in other optoelectronic devices where toxicity and stability are a concern.