Threshold switching in vertically aligned MoS2/SiOx heterostructures based on silver ion migration

npj 2D Materials and Applications, vol. 9

Abstract

Abstract Threshold switching (TS) is a non-permanent change in electrical resistance controlled by voltage modulation in two-terminal devices. Silver (Ag) filament-based TS has been observed in two-dimensional transition metal dichalcogenides, which are promising due to their van der Waals gaps, facilitating ion migration and filament formation without disturbing covalent bonds. This work demonstrates the heterostructure growth of vertically aligned molybdenum disulfide (VAMoS 2 ) with an amorphous silicon oxide (SiO x ) layer after sulfurization. Ag ion migration through this material stack enables TS. Our Ag/SiO x /VAMoS 2 /Au devices exhibit low switching voltages of ~0.63 V, high on-state currents over 200 μA, and stable switching exceeding 10⁴ cycles. A physics-based dynamical model identifies two rate-limiting steps for filament formation, and the simulated switching kinetics align with experimental results. Our devices achieve fast switching in 311 ns and spontaneous relaxation in 233 ns. These findings advance understanding of switching mechanisms and highlight their potential for memory and neuromorphic computing applications.

Authors 11

1. Jimin Lee Aachen Chair of Electronic Devices

   RWTH Aachen University

   Affiliation as printed

   Chair of Electronic Devices, RWTH Aachen University, Aachen, Germany

2. Rana Walied Ahmad

   Forschungszentrum Jülich · Jülich Aachen Research Alliance

   Affiliation as printed

   JARA-Fit and Peter Grünberg Institute (PGI-7), Forschungszentrum Jülich GmbH, Jülich, Germany

3. Sofía Cruces Aachen Chair of Electronic Devices

   RWTH Aachen University

   Affiliation as printed

   Chair of Electronic Devices, RWTH Aachen University, Aachen, Germany

4. Dennis Braun Aachen Chair of Electronic Devices

   RWTH Aachen University

   Affiliation as printed

   Chair of Electronic Devices, RWTH Aachen University, Aachen, Germany

5. Lukas Völkel Aachen Chair of Electronic Devices

   RWTH Aachen University

   Affiliation as printed

   Chair of Electronic Devices, RWTH Aachen University, Aachen, Germany

6. Ke Ran Aachen AMO GmbH Advanced Microelectronic Center Aachen Central Facility for Electron Microscopy

   Forschungszentrum Jülich · Ernst Ruska Centre · AMO (Germany) · RWTH Aachen University

   Affiliation as printed

   AMO GmbH, Advanced Microelectronic Center Aachen, Aachen, Germany

   Central Facility for Electron Microscopy, RWTH Aachen University, Aachen, Germany

   Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Jülich, Germany

7. Vasilis A. Maroufidis Aachen Central Facility for Electron Microscopy

   RWTH Aachen University

   Affiliation as printed

   Central Facility for Electron Microscopy, RWTH Aachen University, Aachen, Germany

8. Joachim Mayer Aachen Central Facility for Electron Microscopy

   Forschungszentrum Jülich · Ernst Ruska Centre · RWTH Aachen University

   Affiliation as printed

   Central Facility for Electron Microscopy, RWTH Aachen University, Aachen, Germany

   Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Jülich, Germany

9. Stephan Menzel

   Forschungszentrum Jülich · Jülich Aachen Research Alliance

   Affiliation as printed

   JARA-Fit and Peter Grünberg Institute (PGI-7), Forschungszentrum Jülich GmbH, Jülich, Germany

10. Alwin Daus corresponding Aachen Chair of Electronic Devices

    University of Stuttgart · RWTH Aachen University

    Affiliation as printed

    Chair of Electronic Devices, RWTH Aachen University, Aachen, Germany

    Institute of Semiconductor Engineering, University of Stuttgart, Stuttgart, Germany

11. Max C. Lemme corresponding Aachen AMO GmbH Advanced Microelectronic Center Aachen Chair of Electronic Devices

    AMO (Germany) · RWTH Aachen University

    Affiliation as printed

    AMO GmbH, Advanced Microelectronic Center Aachen, Aachen, Germany

    Chair of Electronic Devices, RWTH Aachen University, Aachen, Germany