Multi-Stimuli-Responsive Synapse Based on Vertical van der Waals Heterostructures

Abstract

Brain-inspired intelligent systems demand diverse neuromorphic devices beyond simple functionalities. Merging biomimetic sensing with weight-updating capabilities in artificial synaptic devices represents one of the key research focuses. Here, we report a multiresponsive synapse device that integrates synaptic and optical-sensing functions. The device adopts vertically stacked graphene/h-BN/WSe2 heterostructures, including an ultrahigh-mobility readout layer, a weight-control layer, and a dual-stimuli-responsive layer. The unique structure endows synapse devices with excellent synaptic plasticity, short response time (3 μs), and excellent optical responsivity (105 A/W). To demonstrate the application in neuromorphic computing, handwritten digit recognition was simulated based on an unsupervised spiking neural network (SNN) with a precision of 90.89%, well comparable with the state-of-the-art results. Furthermore, multiterminal neuromorphic devices are demonstrated to mimic dendritic integration and photoswitching logic. Different from other synaptic devices, the research work validates multifunctional integration in synaptic devices, supporting the potential fusion of sensing and self-learning in neuromorphic networks.

Introduction of defects in hexagonal boron nitride for vacancy-based 2D memristors

“…S2, † indicating the existence of defect levels. 22 With an increase in carbon doping density, the color of the h-BN crystals becomes deeper yellow (Fig. S2 †), further confirming the introduction of carbon during the growth process.…”

One-Step Preparation of Semiconductor/Dielectric Bilayer Structures for the Simulation of Flexible Bionic Photonic Synapses

“…38 Among them, PPF is one of the typical forms of STP, which plays an indispensable role in the realization of nervous system functions and is considered to be the key factor for biological synaptic information processing. 39 The typical PPF behavior was successfully simulated, as shown in Figure 3c. After the irradiation of 532 nm light with a light intensity of 6.99 mW cm −2 for 2 s, a single EPSC behavior appeared.…”

“…STP is a transient synaptic weight modulation process in which EPSC lasts only hundreds to thousands of milliseconds and then returns to the initial state . Among them, PPF is one of the typical forms of STP, which plays an indispensable role in the realization of nervous system functions and is considered to be the key factor for biological synaptic information processing . The typical PPF behavior was successfully simulated, as shown in Figure c.…”

2D-Material-Based Volatile and Nonvolatile Memristive Devices for Neuromorphic Computing

“…These results indicate that current synaptic devices have potential applications in direction recognition. In addition, 2D materials are usually used as charge-trapping layers in synaptic devices. , For instance, Zhou et al reported a 2D van der Waals heterojunction synaptic transistor, which was based on the structure of graphene/h-BN/WSe 2 (Figure d) . Graphene served as the p-type channel, and h-BN was used as the charge-trapping layer.…”

“…(f) The mimicked LTP/LTD based on graphene/h-BN/WSe 2 synaptic device. Reproduced with permission from ref . Copyright 2022 American Chemical Society.…”