Nonvolatile Memory Device Based on the Ferroelectric Metal/Ferroelectric Semiconductor Junction

The ferroelectric tunnel junction (FTJ) is a competitive candidate for post-Moore nonvolatile memories due to its low power consumption and nonvolatility, with its performance being strongly dependent on the conditions for contact between the ferroelectric material and the metal electrode. The development of two-dimensional materials in recent years has offered new opportunities such as functional metal layers, which is challenging for traditional FTJ systems. Here, we introduce the newly discovered ferroelectric metal WTe₂ as the electrode to construct WTe₂/α-In₂Se₃/Au ferroelectric semiconductor junctions. The interplay between the ferroelectricity in the van der Waals electrode and tunnel junction leads to the emergence of novel device characteristics, including concomitant multiresistance levels, a low switching voltage (<2 V), and a high on/off ratio (>10⁵). Using ferroelectric metal as the electrode for the ferroelectric tunnel/semiconductor junction offers an alternative approach to low-power and high-density ferroelectric memory devices.