Gate-Controlled Three-Terminal ZnO Nanoparticle Optoelectronic Synaptic Devices for In-Sensor Neuromorphic Memory...

Area of Science:

• Materials Science
• Neuroscience
• Electrical Engineering

Background:

• Neuromorphic computing aims to mimic the human brain's efficiency.
• Synaptic devices are crucial for in-sensor memory and processing.
• Optoelectronic devices offer potential for light-controlled neural functions.

Purpose of the Study:

• To develop a gate-tunable, three-terminal optoelectronic synaptic device.
• To investigate the role of gate voltage in modulating synaptic plasticity and memory.
• To explore ZnO nanoparticles for neuromorphic in-sensor memory applications.

Main Methods:

• Fabrication of an Al/ZnO nanoparticles (NPs)/SiO2/Si synaptic device via spin coating.
• Characterization of UV-induced excitatory post-synaptic current (EPSC) responses.
• Analysis of gate voltage modulation, paired-pulse facilitation (PPF), and forgetting rates.
• Demonstration of a 3x3 synaptic device array for visual memory mapping.

Main Results:

• The device exhibited strong UV-induced EPSC responses modulated by gate voltage via charge injection.
• Gate voltage significantly influenced synaptic weight, with PPF values reaching 185%.
• Improved learning efficiency and long-term memory retention were observed under negative gate bias.
• Visual memory formation was successfully visualized using EPSC-based color mapping.

Conclusions:

• ZnO NP-based optoelectronic synaptic devices are promising for energy-efficient, light-driven neuromorphic computing.
• Gate-voltage-induced charge injection is critical for controlling optical potentiation and electrical depression.
• The developed device demonstrates effective modulation of synaptic plasticity and memory characteristics.