In this work, we present a clear evidence, based on numerical simulations and experiments, that the polarization compensation due to trapped charge strongly influences the ON/OFF ratio in Hf0.5Zr0.5O2 (HZO)-based ferroelectric tunnel junctions (FTJs). Furthermore, we identify and explain compensation conditions that enable an optimal operation of FTJs. Our results provide both key physical insights and design guidelines for the operation of FTJs as multilevel synaptic devices.
