Abstract
In the Post-Moore Era, the neuromorphic computing has been mainly focused on breaking the von Neumann bottlenecks. Memristor has been proposed as a key part for the neuromorphic computing architectures, which can be used to emulate the synaptic plasticities of human brain. Ferroelectric memristor is a breakthrough for memristive devices on account of its reliable-nonvolatile storage, low-write/read latency, and tunable-conductive states. However, among the reported ferroelectric memristors, the mechanisms of resistive-switching are still under debate. In addition, the research of emulation of the brain synapses using ferroelectric memristors needs to be further investigated. Herein, the Cu/PbZr0.52Ti0.48O3 (PZT)/Pt ferroelectric memristors have been fabricated. The devices are able to realize the transformation from threshold switching behaviors to resistive switching behaviors. The synaptic plasticities, including excitatory post-synaptic current (EPSC), paired-pulse facilitation (PPF), paired-pulse depression (PPD), and spike time-dependent plasticity (STDP) have been mimicked by the PZT devices. Furthermore, the mechanisms of PZT devices based on the interface barrier and conductive filament models have been investigated by first-principles calculation. This work may contribute to the applications of ferroelectric memristors in neuromorphic computing systems.
Tunneling of photon-generated carrier in the interface barrier induced resistive switching memory behaviour
