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Updated: Jul 14, 2026
09:49
In Situ Transmission Electron Microscopy with Biasing and Fabrication of Asymmetric Crossbars Based on Mixed-Phased a-VOx
Published on: May 13, 2020
Anisotropic Memristive Switching in NbOCl2 Enabled by Directional Oxygen Ion Migration
Caokun Wang1, Yun Ji1, Sanchali Mitra2
1Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, Singapore.
Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
|July 13, 2026
Summary
Directional ion transport in anisotropic 2D materials enables novel memristive devices. NbOCl2 lateral devices show orientation-dependent switching, mimicking synaptic functions for neuromorphic computing.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Anisotropic two-dimensional (2D) materials offer unique pathways for memristive device engineering.
- Directional ion transport in such materials remains an underexplored area for advanced functionalities.
Purpose of the Study:
- To demonstrate orientation-dependent memristive switching in layered NbOCl2 lateral devices.
- To investigate the underlying mechanisms of anisotropic resistive switching.
- To explore the potential of NbOCl2 for neuromorphic computing and reservoir applications.
Main Methods:
- Fabrication of lateral devices using layered NbOCl2.
- Electrical characterization of memristive switching behavior along different crystallographic axes (c-axis vs. b-axis).
- First-principles calculations to elucidate ion migration mechanisms and Schottky barrier modulation.
- Implementation of the NbOCl2 memristor in a physical reservoir for handwritten digit recognition (MNIST dataset).
Main Results:
- NbOCl2 lateral devices exhibit strongly orientation-dependent memristive switching, with hysteresis observed exclusively along the c-axis.
- C-axis devices demonstrate forming-free, volatile memristive behavior with stable on/off ratios and good reproducibility.
- Direction-dependent oxygen-ion migration and vacancy propagation were identified as the origin of anisotropic switching, modulating the Pd/NbOCl2 Schottky barrier.
- The memristor successfully emulated short-term synaptic plasticity and achieved 94.3% accuracy in MNIST recognition when used as a physical reservoir.
Conclusions:
- NbOCl2 is identified as a promising anisotropic material for memristive applications.
- Directional ion migration in 2D materials presents a versatile strategy for developing neuromorphic hardware.
- The study highlights the potential of NbOCl2 memristors for reservoir computing and other advanced electronic functionalities.
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