High-efficiency resistive switch and artificial synaptic simulation in antimony-based perovskite devices

Three kinds of Cs3Sb2X9 (X=I, Br, Cl) perovskite films have been prepared to fabricate the resistive memory devices with the structure of Al/Cs3Sb2X9 (X=I, Br, Cl)/indium tin oxide (ITO) glass. All devices exhibited a bipolar resistive switching behavior at room temperature by applying scanning voltage of 0 → 1 → 0→ −1.8 → 0 V. The switching voltages in the Al/Cs3Sb2X9 (X=I, Br, Cl)/ITO devices gradually decreased with the X from I, Br to Cl due to the different migration rates of halide vacancy in perovskite films, which is confirmed by the first-principles calculations of activation energy. The ON/OFF ratio under the reading voltage of 0.1 V significantly increased up to 100 in the Al/Cs3Sb2Cl9/ITO device, which is nearly 10 and 3 times larger than that of the Al/Cs3Sb2I9/ITO device and the Al/Cs3Sb2Br9/ITO device, respectively. The endurance cycles and retention time of current devices were evaluated, showing the excellent electrical stability. Importantly, the three kinds of Al/Cs3Sb2X9 (X=I, Br, Cl)/ITO device can successfully simulate the short-term plasticity of biological synapse. The Al/Cs3Sb2Cl9/ITO device showed the highest paired-pulsed facilitation index compared with that of other two devices, which was explored for the long-term plasticity and learning experience processes of synapse. In addition, the Al/Cs3Sb2Cl9/ITO device established associative learning behavior by simulating the Pavlov’s dog experiment.