Light-modulated synaptic plasticity of SrTiO3:Ru/CuAlO2 bilayer based memristors for artificial visual system

With the rapid development of intelligent era, machine vision based on von Neumann architecture will face a bottleneck, while the developing neuromorphic computing is one of the most promising options to solve the bottleneck. The key step is to enable the artificial devices to simulate the behaviors of biological synapses, and light-modulated memristors can be applied in neuromorphic computing to build artificial visual systems. Here, a bilayer memristive film of SrTiO₃ /CuAlO₂ was chosen to construct a two-terminal artificial synaptic sample with construction of ITO/SrTiO₃:Ru/CuAlO₂/ITO, in which the SrTiO₃ layer was doped by Ruthenium (Ru) in order to enhance the light response from ultraviolet to visible range. It is found that the number of interior carries in the memristor could be generated by exterior stimulation of light, and the fabricated memristor could successfully mimic multiple synaptic functions of the biological synapse like excitatory postsynaptic current, short/long-term plasticity transform, paired-pulse facilitation and so on. The obtained excellent synaptic plasticities and optoelectronic properties of our light-modulated memristor have shown a potential in the machine vision and artificial neuromorphic computing systems in the near future.