Effect of a semiconductor electrode on the tunneling electroresistance in ferroelectric tunneling junction

We report the tunneling electroresistance effect (TER) in a Pt/BaTiO3(BTO)/Nb:SrTiO3 (n-STO) ferroelectric tunnel junction (FTJ). Using transmission electron microscopy, X-ray photoelectron spectroscopy, and piezoresponse force microscopy, we find that the thick BaTiO3 (5 nm) film is epitaxial and of high quality. A large ON/OFF resistance ratio of more than 10(4)% at room temperature is observed. Our experimental results as well as theoretical modeling reveal that the depletion region near the BTO/n-STO interface can be electrically modulated via ferroelectric polarization, which plays a key role for the TER effect. Moreover, both long retention and high switching reproducibility are observed in the Pt/BTO/n-STO FTJ. Our results provide some fundamental understandings of the TER mechanism in the FTJs using a semiconductor electrode and will be useful for FTJ-based nonvolatile devices design. Published by AIP Publishing.