Artificial Optoelectronic Synapses Based on Light-Controllable Ferroelectric Semiconductor Memristor

Numerous synaptic devices have been explored for the next generation of energy-efficient computing techniques. Among them, optoelectronic synaptic devices based on semiconductor/ferroelectric heterostructures have received a lot of attention lately due to their amazing parallelism, efficiency, and fault tolerance properties. However, polarizing the ferroelectric layer or gating the dielectric layer is necessary to achieve tunable synaptic functions, which generally causes an increase in energy consumption and complex manufacturing processes. Here, a simple and efficient method is demonstrated to develop a tunable optoelectronic synaptic device based on a single ferroelectric semiconductor, BiFeO3-BaTiO3 (BF-BT). Multi-essential synaptic functions including short-term plasticity, paired-pulse facilitation, and long-term plasticity are all satisfactorily replicated by the memristor device. More significantly, light-controllable synaptic behaviors are realized by altering the ferroelectric polarization state of BF-BT. Synaptic devices' relaxation characteristics enable simulation of the effects of positive/negative emotions on learning and forgetting processes. This study highlights the potential of the ferroelectric semiconductor memristor in constructing the efficient optoelectronic synapses for future neuromorphic electronics with the ability to learn and sense optical information.