Achieving ultrahigh synaptic potentiation with a two terminal device based on a solution processed Cs3Bi2Br9-MoS2 hybrid

Abstract

Synaptic devices based on functional materials such as metal halide perovskites and two-dimensional transition metal dichalcogenides have shown great potential for next-generation memory and computing applications. However, they often suffer from nonlinear weight update and rapid saturation. Here, we report a two-terminal synaptic device based on a solution processed hybrid material comprising liquid-exfoliated MoS2 nanosheets and in-situ deposited Cs3Bi2Br9 perovskite. The device demonstrated excellent synaptic properties, including a high paired-pulse facilitation (PPF) index of over 230%, a long retention time of 860 s, and most importantly, highly linear long-term potentiation (LTP). We attributed this enhancement to the favorable energy offset at the CBB-MoS₂ interface and presence of interface potential well. When empirical device data were incorporated into a convolutional neural network for handwritten digit recognition, an accuracy up to 96% was achieved, and maintained at above 85% across a wide humidity range (13-75% RH), demonstrating its potential for neuromorphic computing in complex environments.