4H-SiC Homojunction Photogated Synapses Enabling High-Temperature Neuromorphic Computing.

Area of Science:

• Materials Science
• Optoelectronics
• Neuromorphic Computing

Background:

• Current ultraviolet optoelectronic synapses (UVOSs) suffer from thermal instability, limiting their use in high-temperature environments.
• UVOSs are crucial for applications like secure communication, fire warning, and planetary exploration.

Purpose of the Study:

• To develop high-temperature-resistant UVOSs.
• To investigate the synaptic behavior of 4H-SiC homojunctions at elevated temperatures.
• To demonstrate the potential of these devices in high-temperature neuromorphic computing.

Main Methods:

• Fabrication of p-n 4H-SiC homojunction devices.
• Characterization of photogated synaptic behavior at temperatures up to 350°C in ambient air.
• Emulation of information encryption, image learning-memory, and handwritten digit recognition using a 4H-SiC synapse array.

Main Results:

• Demonstrated robust light-stimulated synaptic behavior in 4H-SiC homojunctions at 350°C without encapsulation.
• Achieved synaptic device operating temperatures significantly higher than previously reported UVOSs.
• Successfully emulated information encryption and image learning-memory at 350°C.
• Achieved up to 95% accuracy in handwritten digit recognition simulations using a 4H-SiC photogated synapse array.

Conclusions:

• 4H-SiC homojunctions offer a viable platform for creating high-temperature-resistant UVOSs.
• The photogating effect in 4H-SiC enables stable synaptic function in harsh thermal conditions.
• This work presents a promising strategy for advancing UVOS technology for high-temperature neuromorphic applications.