Amorphous Ga₂O₃ Based Erasable Two‐Terminal Artificial Photonic Synapses

Abstract Photonic synapses have garnered significant attention in visual sensing due to their ability to sense and store optical information in high parallel. Compared to three‐terminal devices, two‐terminal photonic synapses offer a simpler structure and are easier to integrate with silicon readout integrated circuits. However, achieving an efficient erasure function in two‐terminal photonic synapses has posed a formidable challenge, thereby limiting their broader application. Here, a two‐terminal bend‐erasing photonic synaptic device is designed and fabricated based on amorphous Ga 2 O 3 (a‐Ga 2 O 3 ) films by regulating oxygen vacancies (ranging from 25.6–44.4%). As a result, a‐Ga 2 O 3 photonic synapses optimized by vacancy control engineering demonstrate ultra‐high storage bit‐widths exceeding 5 bits and fundamental synaptic functions. In addition, a 5 × 5 photonic synapse array is constructed. After ten consecutive UV pulse stimulations, the pattern retains a memory level of 30.7% after 120 s of attenuation, reflecting the excellent storage performance. These synaptic functions are also observed in the flexible a‐Ga 2 O 3 device, and data erasure is realized by straightforward mechanical bending of the device. This study provides a low‐cost method to fabricate erasable two‐terminal photonic synapses, which will promote the development of UV artificial retinas and bionic eyes, paving the way for future innovations in optoelectronic applications and neuromorphic systems.