Lead-free monocrystalline perovskite resistive switching device for temporal information processing

Lead-free halide perovskites are emerging as promising candidate for practical application of optoelectronic devices due to their nontoxicity. Unfortunately, previously-reported lead-free halide perovskites-based resistive switching devices suffer from high leakage and operating current stemmed from the intrinsic nature of polycrystalline film with a great amount of grain boundaries and pin-holes. Here, we report for the first time a monocrystalline lead-free Cs3Sb2Br9 perovskite nanoflake based lateral-structured device capable of combining nonvolatile bipolar switching and threshold switching with record-low switching electric field of 2.2 × 105 V m−1. Confirmed by elemental analysis and theoretical calculation, migration of highly mobile Br vacancy with low activation energy in defects-free monocrystalline Cs3Sb2Br9 is believed to be responsible for resistive switching. Short-term Ca2+ dynamics of biological synapses were then imitated by Cs3Sb2Br9 resistive switching devices which were further implemented as an effective reservoir element. The construction of neural network-based reservoir computing system to efficiently process temporal information can be realized since its conductance states are determined by the history of external simulation.