Van der Waals Ferroelectric Halide Perovskite Artificial Synapse

Abstract

Ferroelectricity is promising in emulating the synaptic characteristics of human brains. Utilizing ferroelectricity for brain-inspired computing is proposed as a feasible route to address technical challenges in memory and computing. Here, we demonstrate the use of a ferroelectric van der Waals (vdW) halide perovskite for synaptic emulation. The two-terminal ferroelectric synapse based on the vdW material (R)-(\ensuremath{-})-1-cyclohexylethylammonium)${\mathrm{PbI}}_{3}$ (R-CYHEA${\mathrm{PbI}}_{3}$) exhibits voltage-pulse-dependent weight modulation with a total on:off ratio of 50 and good endurance up to ${10}^{7}$ cycles. The energy consumption per synaptic operation for both short-term plasticity and long-term plasticity reaches the picojoule level. The device also shows reasonable write linearity and small cycle-to-cycle variation, as well as promising spike-timing-dependent plasticity and a paired-pulse-facilitation function. Numerical simulations with the R-CYHEA${\mathrm{PbI}}_{3}$-synapse-based neural network suggest the potential of R-CYHEA${\mathrm{PbI}}_{3}$ synapses for pattern recognition. Ferroelectric vdW halide perovskites provide opportunities for exploiting their dimensionality, superior optoelectronic properties, and mild material-processing conditions for engineering of the synaptic device performance.