MoS2-Based Synaptic Transistor for Neuromorphic Computing and Encoded Optical Communication

Abstract

Two-dimensional (2D) transition metal dichalcogenides (TMDs) have attracted considerable attention for next-generation electronic and optoelectronic devices due to their atomically thin structure, tunable bandgap, and strong light-matter interactions. In this work, we present a facile approach by employing 2D molybdenum disulfide (MoS2) to fabricate an optoelectronic artificial synapse, emphasizing its potential for neuromorphic computing and encoded optical communication. The MoS2-based field-effect transistor (FET) exhibits n-type semiconducting behavior with a current on/off ratio (ION/IOFF) of ∼2.5 × 108 and a large clockwise hysteresis in its transfer characteristics arising from charge trapping defects at the MoS2/SiO2 interface. A memory window of ∼41 V is observed under a gate voltage sweep range of ±60 V, and the memory effect can be gradually modulated from 1 V to 41 V by varying the sweeping range of the Si gate from ±10 to ±60 V. The device demonstrates optically controllable synaptic plasticity under 365 nm UV stimulation, exhibiting key neuromorphic functionalities such as paired-pulse facilitation (PPF), excitatory postsynaptic current (EPSC), spike-number-dependent plasticity (SNDP), and spike-time-dependent plasticity (STDP). Furthermore, the proposed MoS2 synaptic transistor enables encoded optical communication based on temporal pulse-width modulation, where optically encoded signals are directly decoded through distinct EPSC responses. This capability highlights the robustness of the device for optically encoded information processing and its potential for low-power encoded communication, neuromorphic photonic interfaces, and brain-inspired computing systems.