Dual-Mode Conversion of Photodetector and Neuromorphic Vision Sensor via Bias Voltage Regulation on a Single Device.

Area of Science:

• Materials Science
• Optoelectronics
• Neuromorphic Engineering

Background:

• Integrating photodetectors and neuromorphic vision sensors (NVS) is challenging due to differing response speeds.
• Existing devices often require separate components, increasing complexity and size.

Purpose of the Study:

• To fabricate a single optoelectronic device capable of performing both photodetector and NVS functions.
• To overcome the speed discrepancy challenge between photodetectors and NVS.

Main Methods:

• Fabrication of a trench-bridged GaN/Ga2O3/GaN back-to-back double heterojunction array.
• Utilizing oxygen vacancy ionization/de-ionization in Ga2O3 to modulate photoresponse.
• Adjusting bias voltage to switch between photodetector and NVS modes.

Main Results:

• The device exhibits fast photoresponse at low voltages and persistent photoconductivity at high voltages.
• Successfully demonstrated dual functionality as a photodetector (fast imaging, optical communication) and NVS (image sensing, memory, pre-processing).
• NVS pre-processing significantly improved recognition accuracy and efficiency.

Conclusions:

• A single GaN/Ga2O3/GaN device can achieve both photodetector and NVS functionalities by voltage control.
• This approach offers a new pathway for complex optoelectronic devices.
• Enables advanced robotic vision systems and neuromorphic computing applications.