Artificial 2D van der Waals Synapse Devices via Interfacial Engineering for Neuromorphic Systems

Area of Science:

• Materials Science
• Neuroscience
• Electrical Engineering

Background:

• Neuromorphic hardware aims to mimic the brain's efficiency using artificial synapse devices.
• Current artificial synapse research requires a physical parameter to effectively modulate synaptic plasticity.
• Conventional silicon-based complementary metal-oxide semiconductor (CMOS) technology faces limitations in developing advanced neuromorphic systems.

Purpose of the Study:

• To design and investigate a novel two-dimensional artificial synapse architecture.
• To identify and utilize a physical parameter for modulating synaptic plasticity in artificial synapses.
• To overcome limitations of conventional silicon-based technologies for brain-inspired computing.

Main Methods:

• Fabrication of a novel two-dimensional heterostructure: NbSe2/WSe2/Nb2O5 on an SiO2/p+ Si substrate.
• Utilized NbSe2 as the metal electrode, WSe2 as the active channel, and Nb2O5 as the conductance-modulating layer.
• Investigated the effect of Nb2O5 interlayer thickness on synaptic plasticity and post-synaptic current.

Main Results:

• Successfully modulated post-synaptic current by varying the thickness of the Nb2O5 interlayer.
• Demonstrated that a thicker Nb2O5 interlayer results in a higher synapse spike current.
• Observed stronger synaptic interaction in sequential pulse mode with increased interlayer thickness.

Conclusions:

• The thickness of the Nb2O5 interlayer is a key physical parameter for controlling synaptic plasticity.
• This novel heterostructure facilitates the development of reliable and controllable synaptic devices.
• The findings contribute to the realization of integrated neuromorphic systems inspired by the human brain.