Synaptic Plasticity Simulation of Optoelectronic Memristors Based on the (SrTiO3)x/(BaTiO3)y/(CaTiO3)z Ferroelectric Superlattices

In this work, the optoelectronic memristors were fabricated based on the (SrTiO₃)_x/(BaTiO₃)_y/(CaTiO₃)_z (SBCxyz) superlattices and their optoelectronic response synaptic plasticity was studied in detail. It was found that the superlattices exhibited stable and gradual polarization switching behavior controlled by an external electric field. Particularly in the SBC242 superlattice, the asymmetric periodic structure led to an enhancement of remnant polarization. Under the stimulation of 500 positive and negative pulses, the SBC242 memristor exhibited highly recognizable short-circuit current. Among them, the short-circuit photocurrent of the SBC242 superlattice memristor could reach up to 20.34 nA. More interestingly, the memristors also exhibited good device durability and repeatability, as well as clear synaptic behaviors such as light adaptation behavior, paired-pulse depression, long-term potentiation and long-term depression. Overall, this study revealed the great potential of optoelectronic memristors based on the BaTiO₃-based superlattices in simulating synaptic performance.