An interface-engineered three-channel synapse using staggered transition metal dichalcogenides/ferroelectric heterojunctions

Ferroelectric tunnel junctions (FTJs) are widely explored for information storage and neuromorphic computing, typically employing a two-terminal configuration. Integrating additional terminals enhances modulation flexibility, while the interface effects can precisely control the linearity and symmetry of polarization switching dynamics. Here, we fabricated a three-channel FTJ-like device based on 1 T′-MoTe₂/2H-MoS₂/BaTiO₃/La_0.7Sr_0.3MnO₃ heterostructure. The upgraded architecture effectively integrates three independent FTJs into a single device and enables interface effects as additional strategies for polarization modulation. The staggered 1 T′-MoTe₂/2H-MoS₂ heterostructure as top electrodes precisely controls the ferroelectric polarization switching dynamics by interfacial interactions, including band alignment engineering and interface polarization field, thereby achieving diode, non-volatile memory, and synaptic plasticity functionalities. In addition, distinct lateral charge transfer through the 1 T′-MoTe₂/2H-MoS₂ interface introduces an additional polarization modulation strategy. Notably, short-term and long-term synaptic plasticity with excellent linearity and symmetry have been achieved, exhibiting optimal non-linearity factors of −0.161/−0.062. These properties enabled the associated neural network to achieve recognition accuracies of 89.74 %, 94.86 %, and 93.02 % in the corresponding three junctions (approaching the 95.44 % ideal accuracy), thereby demonstrating a high-performance synaptic device with three effective channels. These results offer a new design of densely integrated ferroelectric devices with rich tunability, promoting the frontier of artificial synapse-based on-chip in-memory computing.