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Graphene-In2Se3 van der Waals Heterojunction Neuristor for Optical In-Memory Bimodal Operation
journal contributionposted on 2023-11-06, 17:33 authored by Subhrajit Mukherjee, Debopriya Dutta, Anurag Ghosh, Elad Koren
Functional diversification at the single-device level has become essential for emerging optical neural network (ONN) development. Stable ferroelectricity harnessed with strong light sensitivity in α-In2Se3 holds great potential for developing ultrathin neuromorphic devices. Herein, we demonstrated an all-2D van der Waals heterostructure-based programmable synaptic field effect transistor (FET) utilizing a ferroelectric α-In2Se3 nanosheet and monolayer graphene. The devices exhibited reconfigurable, multilevel nonvolatile memory (NVM) states, which can be successively modulated by multiple dual-mode (optical and electrical) stimuli and thereby used to realize energy-efficient, heterosynaptic functionalities in a biorealistic fashion. Furthermore, under light illumination, the prototypical device can toggle between volatile (photodetector) and nonvolatile optical random-access memory (ORAM) logic operation, depending upon the ferroelectric-dipole induced band adjustment. Finally, plasticity modulation from short-term to prominent long-term characteristics over a wide dynamic range was demonstrated. The inherent operation mechanism owing to the switchable polarization-induced electronic band alignment and bidirectional barrier height modulation at the heterointerface was revealed by conjugated electronic transport and Kelvin-probe force microscopy (KPFM) measurements. Overall, robust (opto)electronic weight controllability for integrated in-sensor and in-memory logic processors and multibit ORAM systems was readily accomplished by the synergistic ferrophotonic heterostructure properties. Our presented results facilitate the technological implementation of versatile all-2D heterosynapses for next-generation perception, optoelectronic logic systems, and Internet-of-Things (IoT) entities.
wide dynamic rangestable ferroelectricity harnessedprobe force microscopypresented results facilitateholds great potentialdevices exhibited reconfigurableconjugated electronic transportoptoelectronic logic systemsmultilevel nonvolatile memorystrong light sensitivity3 sub2 submemory logic processorsnonvolatile optical randommultibit oram systemslogic operationaccess memorylight illuminationthereby usedtechnological implementationswitchable polarizationsuccessively modulatedrealize energyreadily accomplishedprototypical deviceprominent longplasticity modulationmultiple dualheterosynaptic functionalitiesgeneration perceptiondevice leveldepending uponbiorealistic fashionbecome essential2d heterosynapses