Cerium-Doped Ferroelectric Hf 0.5 Zr 0.5 O 2 Memristors for Low-Variability Multilevel Memory and Synaptic Plasticity

Abstract

Memristors have attracted broad interest for multilevel data storage and neuromorphic computing. However, in many conventional memristors, switching relies on the formation and rupture of conductive pathways, whose instability limits reliable synaptic emulation. Here, we present a cerium-doped hafnium-zirconium oxide (Ce-HZO) ferroelectric thin-film memristor, in which resistance switching can be understood within a polarization-defect-coupled framework involving ferroelectric reversal and vacancy-related processes. The device exhibits a high on/off ratio of ~2×10 4 , long retention over 10 4 s, stable endurance over 10 3 cycles, and multiple programmable resistive states. Under pulse operation, the conductance can be tuned continuously to reproduce long-term potentiation and long-term depression, paired-pulse facilitation, and a pulse-number-controlled transition from short-term plasticity to long-term potentiation. Electrical analysis indicates a field-dependent transport evolution, while X-ray photoelectron spectroscopy (XPS) and O K-edge X-ray absorption spectroscopy (XAS) reveal Ce-induced changes in the local valence and oxygen-related electronic structure. These results show that Ce-HZO is a promising platform for low-variability multilevel memory and neuromorphic hardware.