2D MoS₂ Neuromorphic Devices for Brain‐Like Computational Systems

Abstract

Hardware implementation of artificial synapses/neurons with 2D solid-state devices is of great significance for nanoscale brain-like computational systems. Here, 2D MoS synaptic/neuronal transistors are fabricated by using poly(vinyl alcohol) as the laterally coupled, proton-conducting electrolytes. Fundamental synaptic functions, such as an excitatory postsynaptic current, paired-pulse facilitation, and a dynamic filter for information transmission of biological synapse, are successfully emulated. Most importantly, with multiple input gates and one modulatory gate, spiking-dependent logic operation/modulation, multiplicative neural coding, and neuronal gain modulation are also experimentally demonstrated. The results indicate that the intriguing 2D MoS transistors are also very promising for the next-generation of nanoscale neuromorphic device applications.

A roadmap for electronic grade 2D materials

“…295,296 2D materials can also enable platform for hardware artificial intelligence through neuromorphic devices which can mimic the human brain. 297,298 Heterostructures of 2D materials also offer endless opportunities for novel devices, where the primary challenge is to identify the right stacking or stiching. 299 These futuristic applications will, however, require long term vision and determined and sustained research efforts instead of single prototype demonstration.…”

A Fully Printed Flexible MoS2 Memristive Artificial Synapse with Femtojoule Switching Energy

“…Among the conventional RS media, including transition metal oxides (TMOs, e.g., HfO 2 , Al 2 O 3 , TiO 2 ), [4,9,10,16] polymers, [15] and two-dimensional materials (2DMs), [7,8,[11][12][13][14][17][18][19][20][21] the latter shows great potential to realize printed memristors with their solution processability and inherent flexibility. [9,30,31] In recent years, molybdenum disulfide (MoS 2 ) has emerged as a high-performance RS material [8,[11][12][13][14][17][18][19][20][21] with high switching speed (<15 ns), [13] multiple gate-tuneable resistive states, [8,11,12] and mechanical flexibility (1200 bending cycles). [22][23][24][25][26][27][28][29] However, the presence of defect density/vacancies in solution exfoliated 2DM crystals is found to compromise the electrical performance.…”

“…[1][2][3][4][5] In particular in the non-conventional space of smart applications requiring conformal attachment on non-flat surfaces such as on-body wearables, the notion of system on plastics (SOP) incorporating neuromorphic computing provides a potential solution. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] However, current memristor manufacturing technologies such as chemical vapor deposition (CVD), [7,8,[11][12][13] spin-coating, [14,15] or entire transfer [16] impose enormous challenges on flexible substrates as they suffer from high temperature, low yield and complex sacrificial layer removal. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]…”

Recent Progress in Three‐Terminal Artificial Synapses: From Device to System

“…Single synaptic devices could emulate both STP and LTP characteristics, and showed a very reproducible relaxation process . Multiple presynaptic inputs can be spatiotemporally coupled in multigate 2D MoS 2 neuromorphic devices that are laterally coupled by proton‐conducting poly(vinyl alcohol) (PVA) electrolytes . A synaptic device based on black phosphorus offers intrinsic anisotropy in its synaptic characteristics as a result of its low crystalline symmetry …”