AlGaN/GaN-Based Optoelectronic Synaptic Devices for Neuromorphic Computing

Neuromorphic computing promises to overcome the Von Neumann bottleneck of traditional computers. Optoelectronic synaptic devices are greatly desired given their potential applications in neuromorphic computing. In this work, optoelectronic synaptic devices with long-term memory are fabricated. The devices are based on a GaN/AlGaN/AlN/GaN heterojunction and a SiNx charge trapping layer. Synaptic functionalities including excitatory postsynaptic current, paired pulse facilitation, and transition from short-term memory to long-term memory are realized. The retention time of long-term memory may be more than 10 years, demonstrating the reliable charge storage of the devices. Logic functions are also realized by synergizing the photogating and electrical gating of the devices. The responsivity and specific detectivity are 2.64 x 10(5) A W-1 and 1.79 x 10(16) Jones at the optical power density of 1.4 mW cm(-2), respectively. In addition, the devices have a reconfigurable switch of 1000 cycles with working temperature up to 200 degrees C.