Progress of lead-free perovskite and its resistance switching performance

With the rapid development of the information age, the demand for information storage capacity and miniaturization of memory units has been being increased. However, the commonly used silicon-based flash memory has nearly approached to its physical limit. The resistive switching random access memory (ReRAM) has become one of the promising candidates for the next-generation non-volatile memory due to its simple structure, fast operation speed, excellent flexibility, and long endurance. Recently, we witnessed that the lead halide perovskites, as hot star materials, have been widely used in optoelectronic fields owning to their advantages of low cost, excellent photoelectric properties, and solution process ability. Moreover, the lead halide perovskite has been successfully used as the active layer in ReRAM device because of its tunable bandgap, long charge carrier diffusion length, fast ion migration, and high charge carrier mobility. Whereas the toxicity of lead in halide perovskite is a very horrible problem in lead halide perovskite-based ReRAM devices. The lead-free halide perovskite is considered to be the most promising material for perovskite-based ReRAM devices because it does not contain lead element. Most recently, a large number of scientists from different groups have begun to study lead-free perovskite-based ReRAM devices. For example, tin, bismuth, antimony, and copper-based halide perovskite materials have been utilized in ReRAM devices and exhibited excellent resistance switching (RS) performances. Here in this paper, the recent development of lead-free perovskite and its RS performance are reviewed, including lead-free halide perovskite materials, RS performances, and RS mechanisms of lead-free perovskite-based ReRAM. Finally, the key problems and development prospects of lead-free perovskite-based ReRAM are also presented, which provides a fundamental step towards developing the RS performance based on lead-free halide perovskites.