Photodetectors and neuromorphic vision sensors are pivotal optoelectronic devices involved in sensing and processing optical information.
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Photodetectors, characterized by rapid light response and high sensitivity, find applications in optical sensing, communication, and imaging systems. Conversely, neuromorphic vision sensors possess the ability to perceive, store, and process light signals.
A recent development by Associate Professor Xinglai Zhang, Master student Siyu Feng, and their colleagues at the Institute of Metal Research (IMR) of the Chinese Academy of Sciences introduced a trench-bridged GaN/Ga2O3/GaN heterojunction array device.
Through manipulation of the ionization and de-ionization processes of oxygen vacancies in Ga2O3, the device exhibits volatile and non-volatile photocurrents at low and high voltages, respectively.
This innovation allows for the integration of photodetectors and neuromorphic vision sensors into a single device, offering the flexibility to switch between their roles based on the application scenario. Adjusting the operating voltage enables a seamless transition between the functions of a photodetector and a neuromorphic vision sensor within the same device.
The study unveils the device’s capabilities when operating as a photodetector at low voltage. It demonstrates a swift photoresponse speed and high responsivity, enabling the implementation of complex functionalities such as optically controlled logic circuits, photonic imaging, and optical communication.
The study was reported in the Advanced Materials journal on October 9th, 2023.
Conversely, at high voltage and functioning as a neuromorphic vision sensor, the device simulates neuron/synaptic functions, including paired-pulse facilitation, the transition from short-term to long-term plasticity, learning-experience behavior, and image memory.
Moreover, employing the device for image pre-processing enhances the recognition accuracy and efficiency of images.
This groundbreaking research not only provides a novel approach to achieving advanced functions for both photodetectors and neuromorphic vision sensors within a single device but also opens up possibilities for developing robot vision systems and advancing neuromorphic computing.
Feng, S., et al. (2023) Dual-Mode Conversion of Photodetector and Neuromorphic Vision Sensor via Bias Voltage Regulation on a Single Device. Advanced Materials. doi.org/10.1002/adma.202308090.