Abstract
Ferroelectric memristors have found extensive applications as a type of nonvolatile resistance switching memories in information storage, neuromorphic computing, and image recognition. Their resistance switching mechanisms are phenomenally postulated as the modulation of carrier transport by polarization control over Schottky barriers. However, for over a decade, obtaining direct, comprehensive experimental evidence has remained scarce. Here, we report an approach to experimentally demonstrate the origin of ferroelectric resistance switching using planar van der Waals ferroelectric α-In2Se3 memristors. Through rational interfacial engineering, their initial Schottky barrier heights and polarization screening charges at both terminals can be delicately manipulated. This enables us to find that ferroelectric resistance switching is determined by three independent variables: ferroelectric polarization, Schottky barrier variation, and initial barrier height, as opposed to the generally reported explanation. Inspired by these findings, we demonstrate volatile and nonvolatile ferroelectric memristors with large on/off ratios above 104. Our work can be extended to other planar long-channel and vertical ultrashort-channel ferroelectric memristors to reveal their ferroelectric resistance switching regimes and improve their performances.
Highlights
Ferroelectric memristors have found extensive applications as a type of nonvolatile resistance switching memories in information storage, neuromorphic computing, and image recognition
To confirm the previously postulated ferroelectric resistance switching (FRS) regime, we split it into two critical aspects and separately control each of them—ferroelectric polarization and interface barrier—by interfacial engineering
Despite the presence of large channel currents even above 2000 A/cm[2], remarkable current switching windows can be still discerned for those devices without the intentional introduction of exterior screening charges (Fig. S12). This suggests an incomplete screening of ferroelectric polarization charges over the α-In2Se3 metal interface systems, which contrasts the perfect screening in Dev. 2 and Dev. 4
Summary
Ferroelectric memristors have found extensive applications as a type of nonvolatile resistance switching memories in information storage, neuromorphic computing, and image recognition. Ferroelectric memristors, which have received considerable attention over the past decade[5,6,7,8,9,10,11,12,13], are typically nonvolatile resistance switching devices with a simple two-terminal metal-ferroelectric-metal architecture Based on their carrier transport mechanisms, ferroelectric memristors can be classified into ultrashort-channel and longchannel devices. Emerging van der Waals (vdW) ferroelectric α-In2Se3 was used as a model material to create a planar long-channel device with two terminals This facilitates in situ domain visualization, and enables us to finely engineer charged interfacial molecules and Schottky barriers at both terminals. Our approach is applicable for ultrashort-channel ferroelectric memristors to demonstrate all FRS elements
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call