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. A monocrystalline lead-free Cs3Sb2Br9 memristor capable of combining memristive functions including bipolar, threshold switching and short-term synaptic operation imitating Ca2+ dynamics of biological synapse through migration of highly mobile Br vacancy is reported. Cs3Sb2Br9 memristor-based reservoir can process temporal information and along with readout function letter recognition task is accomplished, offering promising strategy for building hardware efficient and simplified computing architecture. [Display omitted] •A monocrystalline lead-free all-inorganic perovskite Cs3Sb2Br9-based resistive switching devices was reported.•By tuning the channel length, both nonvolatile bipolar and volatile threshold switching were achieved.•The mechanism is confirmed by density functional theory calculation and temperature dependent experiment.•Short-term plasticity was emulated, which allow the devices to process temporal information for reservoir computing.