A simple and efficient synaptic device based on MoTe_2−x O _x /MoTe₂ heterojunction treated with oxygen plasma

Abstract Two-dimensional (2D) materials are widely used in designing and fabricating artificial optoelectronic synapses due to their atomic-level thickness, ultra-high carrier mobility, strong light-matter coupling, and extreme sensitivity to electrostatic modulation. In this work, we present an artificial synapse based on a MoTe_2−x O _x /MoTe₂ heterojunction. Oxygen vacancy defects are introduced on the MoTe₂ surface via oxygen plasma treatment, enabling charge transfer and storage in the channel through defect utilization. The device demonstrates the ability of multi-terminal modulation under electrical and optical pulse stimulation, successfully simulating various synaptic behaviors such as short-term plasticity, long-term plasticity, and paired-pulse facilitation. Additionally, it achieves good synaptic weight update parameters under optoelectronic co-regulation and realizes a 96% image recognition accuracy in the artificial neural network. This work provides new insights into the structural design of 2D material-based photoelectric synapses for neuromorphic computing.