Demonstration of Nonvolatile Storage and Synaptic Functions in All-Two-Dimensional Floating-Gate Transistors Based on MoS₂ Channels

Abstract

With the advent of post-Moore era, the development of memory devices based on bulk materials gradually entered the bottleneck period. Two-dimensional (2D) materials have received much attention due to their excellent optoelectronic and mechanical properties. Also, floating-gate devices based on 2D van der Waals heterostructures have drawn widespread attention in virtue of their great potential for nonvolatile memory. In this paper, a floating-gate device based on a MoS 2 /BN/graphene heterostructure was fabricated and its electrical storage performance and synaptic function were investigated. Finally, the device obtains a switching ratio of close to ∼10 5 , a large storage window of 107.8 V under a sweeping range of ±60 V, good endurance after 1000 cycles, and charge retention capability above 1500 s. In addition, the device can be used as an artificial synapse to simulate a basic synaptic function and achieve a more linear and symmetrical longterm potentiation and long-term depression profiles. At the same time, the constructed convolutional neural network using this device reaches a high recognition accuracy of 95.5% for handwritten numerals after 1000 times training. These results demonstrate the great potential of 2D material floating-gate devices for nonvolatile memory and neuromorphic computing, which pave the way for the development of next-generation memory devices.

A floating-gate field-effect transistor memory device based on organic crystals with a built-in tunneling dielectric by a one-step growth strategy

“…The programing/ erasing switching speeds are comparable to those (∼10 ms) of the reported pentacene-based FG-OFET memory devices 30 and those (∼4 ms) of the reported inorganic semiconductor-based FG-FET memory devices. 31,32 To further improve the programing/erasing speed, it is expected that the optimization of the thickness of the tunneling layer in the memory device is a balancing act between the programming/erasing speed and data retention, which is worth further studying in future work.…”

A metastable small organic molecule for secure memory devices

“…6–16 As part of the family of electronic devices, organic electrical memory devices have attracted enormous attention. 17–33 Recently, stimuli-responsive materials have been introduced into organic electrical memory devices realizing novel performance. For example, Song and co-workers developed photoinduced multilevel memory devices whose performance could be easily tuned and controlled from bistable switching behaviour to tristable switching behaviour through UV light.…”

A synapse with low power consumption based on MoTe2/SnS2 heterostructure

“…In recent years, synaptic devices based on two-dimensional (2D) materials, such as grapheme [8][9][10] and transitionmetal dichalcogenides including MoS 2 [11][12][13], WSe 2 [14][15][16][17], WS 2 [18,19], and InSe [20][21][22] have been successfully developed and exhibited excellent charge storage performance. 2D materials have great potential for highperformance devices with high-density integration and low power consumption due their atomic thickness, absence of lattice mismatch, and compatibility with conventional device technologies.…”

“…The second category is three-terminal flash memory with gate tunability, which has the potential to mimic the neuromorphic behavior of synapses. Since the back gate controls the 'write' operations, the source and drain control 'read' operation, resulting in increased device resistance adjustability and decreased energy consumption [8,16,27,28]. MoTe 2 is a 2D layered material with unique properties, including high current carrier mobility, making it suitable for low-consumption devices.…”