Building Light Stimulated Synaptic Memory Devices for Visual Memory Simulation

Detection and storage of different light information using electronic devices are important to emulate image information learning and memory functions like the human visual system. In this work, the controllable light‐tunable synaptic memory behaviors are demonstrated utilizing photodetector in series with memristor (composite memristor). In other words, the composite memristor has the detection‐storage function to different light information, realizing visual memory simulation. Herein, a new synaptic device with inherent learning and memory functions is realized based on a pn heterostructure memristor. A depletion‐region width modulation model is proposed to explain the memory characteristics. Several essential synaptic functions are imitated. Further, the visual memory array system is built to accomplish the detection and memory processes of patterned light distribution. Importantly, different light information induces different pattern memory characteristics like human eyes. This composite memristor provides a new idea for wider waveband, greater detection range, and more realistic multifunctional electronic eyes. A visual memory array system is built utilizing a Ga2O3‐based photodetector in series with a p‐NiO/n‐ZnO heterostructure memristor to accomplish the detection and memory processes of patterned light distribution, realizing realistic visual memory simulations for simple images. These results will open up possibilities in design and build multifunctional electronic eyes with wider detection wavelength and more realistic visual memory function.