GeTe/MoTe₂ Van der Waals Heterostructures: Enabling Ultralow Voltage Memristors for Nonvolatile Memory and...

Advanced electronic semiconducting Van der Waals heterostructures (HSs) are promising candidates for exploring next-generation nanoelectronics owing to their exceptional electronic properties, which present the possibility of extending their functionalities to diverse potential applications. In this study, GeTe/MoTe₂ HS are explored for nonvolatile memory and neuromorphic-computing applications. Sputter-deposited Ag/GeTe/MoTe₂/Pt HS cross-point devices are fabricated, and they demonstrate memristor behavior at ultralow switching voltages (V_SET: 0.15 V and V_RESET: -0.14 V) with very low energy consumption (≈30 nJ), high memory window, long retention time (10⁴ s), and excellent endurance (10⁵ cycles). Resistive switching is achieved by adjusting the interface between the Ag top electrode and the heterojunction switching layer. Cross-sectional transmission electron microscope images and conductive atomic force microscopy analysis confirm the presence of a conducting filament in the heterojunction switching layer. Further, emulating various synaptic functions of a biological synapse reveals that GeTe/MoTe₂ HS can be utilized for energy-efficient neuromorphic-computing applications. A multilayer perceptron is implemented using the synaptic weights of the Ag/GeTe/MoTe₂/Pt HS device, revealing high pattern accuracy (81.3%). These results indicate that HS devices can be considered a potential solution for high-density memory and artificial intelligence applications.