Combined resistive switching memory and multi-state operation in Terpyridine - based Pd(II) and Fe(III) Complexes for neuromorphic applications

Abstract

Molecular electronic devices with tunable resistance hold significant potential as candidates for next-generation non-volatile memory technology and Neuromorphic computation. By introducing subtle modifications to molecular structures and electronic properties, memory performance can be effectively enhanced through optimized molecular design and intra/intermolecular interactions. Coordination compounds-based resistive memory devices present a low-cost, solution-processable alternative that could align with industrial demands. In this study, we demonstrate by carefully designing and synthesis of a tosylated terpyridine molecule, along with its related tos-tpy-Pd(II) (cationic and diamagnetic) and tos-tpy-Fe(III) (neutral and paramagnetic) complexes, can be utilized for memory and neuromorphic applications. Notably, these complexes exhibit robust responses to electric fields, enabling their operation in low-energy neuromorphic applications. The devices achieved stable memory states (∼ 500 cycles) and demonstrated multistate operations (∼ 1000 cycles). Furthermore, extremely stable synaptic plasticity with a high MNIST handwritten numbers pattern recognition accuracy of ∼ 80–84 \% is achieved through the implementation of artificial neural network (ANN) simulations.