Artificial Synapse Based on a δ-FAPbI<sub>3</sub>/Atomic-Layer-Deposited SnO<sub>2</sub> Bilayer Memristor.

Lee, Sang-Uk; Kim, So-Yeon; Lee, Joo-Hong; Baek, Ji Hyun; Lee, Jin-Wook; Jang, Ho Won; Park, Nam-Gyu · Nano Lett · 2024

basic_science · Level V

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Abstract

Halide perovskite-based resistive switching memory (memristor) has potential in an artificial synapse. However, an abrupt switch behavior observed for a formamidinium lead triiodide (FAPbI<sub>3</sub>)-based memristor is undesirable for an artificial synapse. Here, we report on the δ-FAPbI<sub>3</sub>/atomic-layer-deposited (ALD)-SnO<sub>2</sub> bilayer memristor for gradual analogue resistive switching. In comparison to a single-layer δ-FAPbI<sub>3</sub> memristor, the heterojunction δ-FAPbI<sub>3</sub>/ALD-SnO<sub>2</sub> bilayer effectively reduces the current level in the high-resistance state. The analog resistive switching characteristics of δ-FAPbI<sub>3</sub>/ALD-SnO<sub>2</sub> demonstrate exceptional linearity and potentiation/depression performance, resembling an artificial synapse for neuromorphic computing. The nonlinearity of long-term potentiation and long-term depression is notably decreased from 12.26 to 0.60 and from -8.79 to -3.47, respectively. Moreover, the δ-FAPbI<sub>3</sub>/ALD-SnO<sub>2</sub> bilayer achieves a recognition rate of ≤94.04% based on the modified National Institute of Standards and Technology database (MNIST), establishing its potential in an efficient artificial synapse.