Bio-inspired synaptic behavior simulation in thin-film transistors based on molybdenum disulfide

Area of Science:

• Materials Science
• Nanotechnology
• Neuroscience

Background:

• Synaptic plasticity is crucial for learning and memory in biological systems.
• Mimicking synaptic behavior in artificial devices offers pathways for neuromorphic computing.
• Molybdenum disulfide (MoS2) is a promising 2D material for electronic applications.

Purpose of the Study:

• To simulate synaptic behaviors in transistors utilizing MoS2 as the active layer.
• To investigate the potential of MoS2-based thin-film transistors for neuromorphic computing applications.
• To analyze short-term and long-term plasticity phenomena in MoS2 devices.

Main Methods:

• Fabrication of ambipolar thin-film transistors with MoS2 as the active layer.
• Simulation of excitatory postsynaptic current (EPSC) phenomenon.
• Application of consecutive voltage pulses (±5 V) to induce potentiation and depression.
• Evaluation of paired-pulse facilitation using triangular wave pulses.

Main Results:

• Observed gradual voltage decay simulating EPSC with a slight increase in response current.
• Demonstrated short-term potentiation and depression after ten consecutive pulse tests.
• Achieved significant current transitions (0.14 mA to 28.3 mA) after 92 positive pulses (long-term potentiation).
• Observed current changes after 88 negative pulses, indicating long-term depression.
• Showcased paired-pulse facilitation with the second stimulus pulse current being ~1.2x the first.

Conclusions:

• MoS2-based thin-film transistors effectively simulate synaptic behaviors, including EPSC, potentiation, and depression.
• The observed plasticity phenomena suggest MoS2 is a viable material for developing artificial synaptic devices.
• MoS2 offers significant advantages and prospects for future neuromorphic computing hardware.