Multi-terminal memtransistors from polycrystalline monolayer molybdenum disulfide

Area of Science:

• Materials Science
• Electrical Engineering
• Neuroscience

Background:

• Memristors are crucial for non-volatile memory and neuromorphic computing, offering advantages over flash memory.
• Two-terminal memristors show basic neural function capacity but lack the complexity for advanced functions like heterosynaptic plasticity.
• Existing multi-terminal approaches have failed to integrate memristive switching with transistor functionality.

Purpose of the Study:

• To experimentally realize a multi-terminal hybrid memristor and transistor (memtransistor).
• To investigate the potential of molybdenum disulfide (MoS2) for creating advanced memtransistors.
• To demonstrate complex neuromorphic functions, including heterosynaptic plasticity, using the novel device.

Main Methods:

• Fabrication of multi-terminal memtransistors using polycrystalline monolayer molybdenum disulfide (MoS2).
• Characterization of device performance, including gate tunability, switching ratios, endurance, and retention.
• Utilizing in situ scanning probe microscopy, cryogenic charge transport measurements, and device modeling to understand switching mechanisms.

Main Results:

• Demonstrated a scalable fabrication process for MoS2 memtransistors.
• Achieved four orders of magnitude gate tunability in resistance states with high endurance and retention.
• Exhibited gate-tunable heterosynaptic functionality in six-terminal MoS2 memtransistors, mimicking complex neural plasticity.

Conclusions:

• The developed MoS2 memtransistor seamlessly integrates memristor and transistor functionalities in a multi-terminal configuration.
• This device enables complex neuromorphic learning and advanced synaptic functions not possible with two-terminal memristors.
• The study reveals that bias-induced MoS2 defect motion drives resistive switching by modulating Schottky barrier heights, offering insights into 2D material physics.