| Aug 21, 2025 |
Imaging the switching dynamics of memristors based on 2D materials in real timeResearch team demonstrates for the first time the formation and dissolution of conductive filaments in 2D material-based memristors.(Nanowerk News) A research team from AMO GmbH, RWTH Aachen University (Chair of Electronic Devices), and Forschungszentrum Jülich has made significant progress in understanding the dynamics of conductive filaments within memristive devices based on two-dimensional (2D) materials. |
| Their innovative study employs operando transmission electron microscopy (TEM) to observe these phenomena in real time during device operation in 2D molybdenum disulfide (MoS2) as the switching material, providing unprecedented insights into the behavior of these advanced electronic components for the first time (Nature Communications, "Unraveling the dynamics of conductive filaments in MoS2-based memristors by operando transmission electron microscopy"). |
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| a False color HAADF images acquired at different times during a 0 V → 5 V → 0 V → −5 V → 0 V sweep. Four regions (A1–A4) are defined at the bottom, corresponding to the Pd electrode, the MoS2 channel, the isolated Ag particle, and the Ag electrode, respectively. The red triangles mark the emerging contrast from Ag filaments. b Intensity variation within the four defined areas (ΔA1–ΔA4) as a function of time during the sweep. The corresponding bias voltage is indicated on the top axis. The inset is an enlarged image from the region defined by the dashed rectangle. (click on image to enlarge) |
| Memristors are gaining traction as key elements for neuromorphic computing due to their ability to emulate synaptic functions and efficient information processing. This research focuses on lateral memristive devices constructed from multilayer 2D MoS2 with palladium (Pd) and silver (Ag) electrodes. |
| By combining advanced TEM imaging techniques with electrical measurements, the researchers were able to visualize in real time (“operando”), the formation and migration of Ag conductive filaments under applied bias voltage. This enabled the correlation of the filament dynamics with electrical device performance metrics such as switching voltage and response time. |
| “Conventional techniques like conductive atomic force or scanning tunneling microscopy only capture snapshots before and after switching events in memory devices, missing the critical dynamics that happen in between. Operando TEM, on the other hand, allows us to directly observe how conductive filaments form, evolve, and dissolve inside a device—as it operates. This is especially important for emerging devices based on two-dimensional materials, where filament behavior is still poorly understood. By correlating electrical performance with what we image during operation, we can gain deep insight into filaments dynamics and switching behaviors, ultimately paving the way for more reliable and efficient memory technologies,” explains Dr. Ke Ran, lead author of the article. |
| The findings indicate that the size and distribution of Ag filaments significantly influence switching performance, shedding light on cycle-to-cycle variability observed in memristive devices. The study not only elucidates the microscopic origins of resistive switching but also offers guidance for optimizing device architecture and materials for future applications in artificial intelligence and data storage technologies. |
| “Having TEM experts like Dr. Ran embedded in the device research is invaluable,” says Prof. Max Lemme, Chair of Electronic Devices and Director of AMO GmbH. “Nano-device fabrication, electrical characterization of these novel devices, and their operando analysis require constant feedback and many iterations to be successful, as well as sophisticated infrastructure. I am very proud of the entire team for making this possible.” |
| Source: AMO (Note: Content may be edited for style and length) |
