Conductive Path Mechanism for Bipolar Resistive Switching Characteristics in Lead-Free Perovskite CsSnBr3-Based Nonvolatile Memories

Halide perovskites are intensely studied due to their potential excellent properties in electronic devices. However, the toxicity of lead remains as an obstacle on their way toward large-scale applications. Herein, the lead-free all-inorganic perovskite CsSnBr3 film is used as the switching layer to construct nonvolatile resistive switching (RS) memories and the underlying switching mechanism is systematically explicated. Both memories with Ag/CsSnBr3/Pt and Pt/CsSnBr3/Pt structures exhibit reproducible bipolar RS characteristics, including the large on/off ratios and low reset currents. The RS characteristics are attributed to the formation/rupture of nano-cone-shaped conductive paths under external voltage bias. In addition, compared with Pt/CsSnBr3/Pt device, the Ag/CsSnBr3/Pt device manifests lower operation set/reset voltages, revealing the formation of higher density or stronger conductive paths. This work might pave the way for the lead-free all-inorganic perovskite-based RS memory devices in high performance emerging commercial applications.