A Fluorographene‐Based Synaptic Transistor

Abstract

Exploring brain‐inspired synaptic devices has recently become a new focus of research in nanoelectronic communities. In this emerging field, incorporating 2D materials into three‐terminal synaptic transistors has brought various advantages. However, achieving a stable and long‐term weight‐modulation in these synaptic transistors, which are typically based on interface charge storage, is still a challenge due to the nature of their spontaneous relaxation. The application of an atomically thin fluorographene layer into the synaptic junction region suppresses this issue and improves the efficiency, tunability, and symmetry of the synaptic plasticity as well as establishing a stable weight‐regulation paradigm. These unique properties can be attributed to the dipolar rotation of CF in fluorographene. To obtain a better physical understanding, a vacancy‐dependent CF dipolar rotation model is proposed and supported by hysteresis analysis and density functional theory calculations. As proposed and demonstrated, the unique fluorographene‐based synaptic transistor may be a promising building block for constructing efficient neuromorphic computing hardware.

Artificial van der Waals hybrid synapse and its application to acoustic pattern recognition

“…This vdW-hybrid synaptic device features two signal paths for potentiation and depression operations, which are formed on WSe 2 (for hole transport)/hexagonal-boron nitride ( h -BN) and MoS 2 (for electron transport)/ h -BN heterostructures, respectively. Here, such vdW heterostructures are free from concerns about lattice mismatching owing to the dangling-bond-free surface nature of the vdW materials 33 – 35 , thereby allowing the formation of interfacial defect-free floating gate structure 36 , 37 or the modulation of the number of interfacial traps/dipoles for achieving the synaptic functionalities 12 , 18 , 38 . The potentiation and depression channels are tied by two electrodes, which are defined as the presynaptic and postsynaptic terminals, and the two channels have an individual gate electrode functioning as a weight control terminal (WCT).…”

Flexible and Energy-efficient Synaptic Transistor with Quasi-linear Weight Update Protocol by Inkjet Printing of Orientated Polar-electret/High-k Oxide Hybrid Dielectric

“…Strong dipoles on intrinsic ordered two-dimensional uorographene (FGR) has been proposed in a synaptic transistor to have a large margin weight update under a stimulating voltage as low as 3 V, which demonstrates the signi cance of molecule alignment for energy-e cient synaptic devices based on the polarization mechanism 41 . Although the traits of micro uidic regulation have attracted intense interests in the eld of inkjet printing and are desirable for the alignment of electret molecules, which may be conducive to the orientation of dipoles along the chains, they have not been applied yet in a synaptic transistor.…”

Two-Dimensional Near-Atom-Thickness Materials for Emerging Neuromorphic Devices and Applications

“…Their desirable properties, including atomic thickness, dangling-bond-free surfaces, mechanical strength, high integration density, tunable electrical transport, and optical properties, as well as low energy consumption, make them ideal candidates for applications in a wide range of electronic devices ( Gupta et al., 2015 ; Mas-Ballesté et al., 2011 ; Xia et al., 2017 ). More recently, the applications of 2D materials have been extensively studied for energy-efficient and high-performing artificial synapses ( Arnold et al., 2017 ; Chen et al., 2019c ; Dev et al., 2020 ; Hu et al., 2019 ; Jiang et al., 2017 ; Kalita et al., 2019 ; Kim et al., 2019c ; Krishnaprasad et al., 2019 ; Kumar et al., 2019 ; Li et al., 2018 ; Liu et al., 2019 ; Mao et al., 2019 ; Paul et al., 2019 ; Pradhan et al., 2020 ; Xie et al., 2018a , 2018b ; Xu et al., 2019 ; Yan et al., 2019a ; Yi et al., 2018 ; Zhu et al., 2019 ). Furthermore, owing to their dangling-bonds-free surface and atomically thin nature, a variety of 2D materials-based heterostructures have been developed in spite of their lattice mismatch ( Novoselov et al., 2016 ).…”

“…The unrivaled thinness of 2D materials also enables rapid electrical switching in memristor devices circumventing short channel effects, leading to improved energy efficiency ( Stanford et al., 2018 ). Additionally, 2D materials and their heterostructures can be integrated into transistor-type devices to achieve desired synaptic characteristics owing to the absence of surface/interface defects allowing for precise modulation of surface/interfacial traps ( Liu et al., 2019 ; Seo et al., 2018 ). Therefore, 2D materials hold tremendous prospects for neuromorphic applications in terms of scalability, learning, and energy efficiency.…”