Heterosynaptic MoS₂ Memtransistors Emulating Biological Neuromodulation for Energy‐Efficient Neuromorphic Electronics

Abstract

Heterosynaptic neuromodulation is a key enabler for energy‐efficient and high‐level biological neural processing. However, such manifold synaptic modulation cannot be emulated using conventional memristors and synaptic transistors. Thus, reported herein is a three‐terminal heterosynaptic memtransistor using an intentional‐defect‐generated molybdenum disulfide channel. Particularly, the defect‐mediated space‐charge‐limited conduction in the ultrathin channel results in memristive switching characteristics between the source and drain terminals, which are further modulated using a gate terminal according to the gate‐tuned filling of trap states. The device acts as an artificial synapse controlled by sub‐femtojoule impulses from both the source and gate terminals, consuming lower energy than its biological counterpart. In particular, electrostatic gate modulation, corresponding to biological neuromodulation, additionally regulates the dynamic range and tuning rate of the synaptic weight, independent of the programming (source) impulses. Notably, this heterosynaptic modulation not only improves the learning accuracy and efficiency but also reduces energy consumption in the pattern recognition. Thus, the study presents a new route leading toward the realization of highly networked and energy‐efficient neuromorphic electronics.

Coexisting Phases in Transition Metal Dichalcogenides: Overview, Synthesis, Applications, and Prospects

“…The resistance of these materials can be changed with applied voltage. − Leverage of the atomically thin layers of 2D materials allows precise control of the resistance and enables the replication of synaptic behavior. These materials also feature varied polarization and resistive switching mechanisms, with specific subcategories, including charge trapping, − vacancy migration, − amorphous-to-crystalline phase transition, − and filament formation. − The fusion of memristors and 2D materials holds immense potential for revolutionary data processing and cognitive computing. However, there remains a lack of comprehensive reports on the memristive structures based on the coexisting phases of TMDCs.…”

Plasma Processing and Treatment of 2D Transition Metal Dichalcogenides: Tuning Properties and Defect Engineering

“…Such performance can be enhanced in double-floating gate devices with two plasma-generated HfO x / HfS 2 heterostructures with a large memory window of more than 100 V, a high on/off current ratio of ∼10 7 , a long retention time of more than 5 × 10 3 , and a high accuracy of 96.12% in pattern recognition . Oxidation of MoS 2 channels in MoS 2 -based transistors by UV/O 3 can also enable memristive switching characteristics with potential usage as memtransistors for energy-efficient neuromorphic electronics …”

Submicron Memtransistors Made from Monocrystalline Molybdenum Disulfide

“…4,5 In addition to logic devices, 2D TMDs hold great promise for memory devices owing to effective electrostatic control of band structures. 6 Extensive 2D material memory research has focused on memristors, which are two-terminal passive electronic devices possessing a nonlinear relationship between the resistance and the electrical charge passing through the device. 7 By connection with a transistor (1T) or a selector (1S), a 1T-1R device cell exhibits multilevel memory storage enabled by the gate voltage applied on transistors.…”

“…Two-dimensional (2D) transition-metal dichalcogenides (TMDs) such as monolayer molybdenum disulfide (MoS 2 ) possess atomically thin thicknesses, high carrier mobility, and high on/off current ratios, making them a potential alternative for channel materials in transistors. These properties also make 2D TMDs a promising avenue for extending the scaling limit and breaking through Moore’s law. , In addition to logic devices, 2D TMDs hold great promise for memory devices owing to effective electrostatic control of band structures . Extensive 2D material memory research has focused on memristors, which are two-terminal passive electronic devices possessing a nonlinear relationship between the resistance and the electrical charge passing through the device .…”