Revisiting Ferroelectric-Gated Phototransistors: A Tripartite Synapse-Inspired Approach to In-Sensor Image Processing

Area of Science:

• Materials Science
• Neuroscience
• Electrical Engineering

Background:

• Neuromorphic devices mimic the brain's structure for efficient computation.
• The tripartite synapse, with its third terminal, offers advanced synaptic weight modulation.
• Integrating optical information processing with memory in a single device remains a challenge.

Purpose of the Study:

• To explore the use of an electrically independent terminal for memorizing and processing optical information.
• To develop a ferroelectric-gated phototransistor (FGPT) for advanced neuromorphic vision systems.
• To enhance photonic non-volatile (PNV) characteristics for visual information storage and retrieval.

Main Methods:

• Utilized ferroelectric polymers and organic photoactive channels in the FGPT design.
• Investigated partial polarization switching in the ferroelectric gate insulator for linear channel control.
• Analyzed the photogating effect induced by charge trapping at the interface.

Main Results:

• Demonstrated linear control of the photoactive channel via partial polarization switching.
• Achieved enhanced photonic non-volatile (PNV) characteristics through photogating effects.
• Showcased incremental potentiation and depression of memorized visual information (photoconductance) across a 153 dB dynamic range.
• Validated the FGPT for all-day face recognition with up to a 40% accuracy improvement through in-sensor processing.

Conclusions:

• The developed FGPT effectively integrates optical information processing and memory functions.
• The device exhibits significant potential for next-generation neuromorphic vision applications, including robust face recognition.
• This work advances the development of efficient and high-performance neuromorphic hardware.