Modulating Trapping in Low-Dimensional Lead-Tin Halides for Energy-Efficient Neuromorphic Electronics

: Metal halide perovskites have drawn great attention for neuromorphic electronic devices in recent years, however, the toxicity of lead as well as the variability and energy consumption of operational devices still pose great challenges for further consideration of this material in neuromorphic computing applications. Here, a 2D Ruddlesden-Popper (RP) metal halides system of formulation BA2Pb0.5Sn0.5I4 (BA = n-butylammonium) is prepared that exhibits outstanding resistive switching memory performance after cesium carbonate (Cs2CO3) deposition. In particular, the device exhibits excellent switching characteristics (endurance of 5 × 105 cycles, ON/OFF ratio ≈105) and achieves 90.1% accuracy on the MNIST dataset. More importantly, a novel energy-efficient content addressable memory (CAM) architecture building on perovskite memristive devices for neuromorphic applications, called nCAM, is proposed, which has a minimum energy consumption of ≈0.025 fJ bit/cell. A mechanism involving the manipulation of trapping states through Cs2CO3 deposition is proposed to explain the resistive switching behavior of the memristive device.