Abstract The development of next‐generation in‐memory and neuromorphic computing can be realized with memory transistors based on 2D ferroelectric semiconductors. Among these, In2Se3is the interesting since it possesses ferroelectricity in 2D quintuple layers. Synthesis of large amounts of In2Se3crystals with the desired phase, however, has not been previously achieved. Here, the gram‐scale synthesis of α‐In2Se3crystals using a flash‐within‐flash Joule heating method is demonstrated. This approach allows the synthesis of single‐phase α‐In2Se3crystals regardless of the conductance of precursors in the inner tube and enables the synthesis of gram‐scale quantities of α‐In2Se3crystals. Then, α‐In2Se3flakes are fabricated and used as a 2D ferroelectric semiconductor FET artificial synaptic device platform. By modulating the degree of polarization in α‐In2Se3flakes according to the gate electrical pulses, these devices exhibit distinct essential synaptic behaviors. Their synaptic performance shows excellent and robust reliability under repeated electrical pulses. Finally, it is demonstrated that the synaptic devices achieve an estimated learning accuracy of up to ≈87% for Modified National Institute of Standards and Technology patterns in a single‐layer neural network system.
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Enhanced Synaptic Memory Window and Linearity in Planar In 2 Se 3 Ferroelectric Junctions
Abstract A synaptic memristor using 2D ferroelectric junctions is a promising candidate for future neuromorphic computing with ultra‐low power consumption, parallel computing, and adaptive scalable computing technologies. However, its utilization is restricted due to the limited operational voltage memory window and low on/off current (ION/OFF) ratio of the memristor devices. Here, it is demonstrated that synaptic operations of 2D In2Se3ferroelectric junctions in a planar memristor architecture can reach a voltage memory window as high as 16 V (±8 V) and ION/OFFratio of 108, significantly higher than the current literature values. The power consumption is 10−5 W at the on state, demonstrating low power usage while maintaining a large ION/OFFratio of 108compared to other ferroelectric devices. Moreover, the developed ferroelectric junction mimicked synaptic plasticity through pulses in the pre‐synapse. The nonlinearity factors are obtained 1.25 for LTP, −0.25 for LTD, respectively. The single‐layer perceptron (SLP) and convolutional neural network (CNN) on‐chip training results in an accuracy of up to 90%, compared to the 91% in an ideal synapse device. Furthermore, the incorporation of a 3 nm thick SiO2interface between the α‐In2Se3and the Au electrode resulted in ultrahigh performance among other 2D ferroelectric junction devices to date.
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- Award ID(s):
- 2118806
- PAR ID:
- 10637779
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Advanced Materials
- Volume:
- 37
- Issue:
- 6
- ISSN:
- 0935-9648
- Page Range / eLocation ID:
- 2413178
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Power efficient MoS 2 synaptic devices based on Maxwell–Wagner interfacial charging in binary oxidesAbstract Synaptic devices with tunable weight hold great promise in enabling non-von Neumann architecture for energy efficient computing. However, conventional metal-insulator-metal based two-terminal memristors share the same physical channel for both programming and reading, therefore the programming power consumption is dependent on the synaptic resistance states and can be particularly high when the memristor is in the low resistance states. Three terminal synaptic transistors, on the other hand, allow synchronous programming and reading and have been shown to possess excellent reliability. Here we present a binary oxide based three-terminal MoS2synaptic device, in which the channel conductance can be modulated by interfacial charges generated at the oxide interface driven by Maxwell-Wagner instability. The binary oxide stack serves both as an interfacial charge host and gate dielectrics. Both excitatory and inhibitory behaviors are experimentally realized, and the presynaptic potential polarity can be effectively controlled by engineering the oxide stacking sequence, which is a unique feature compared with existing charge-trap based synaptic devices and provides a new tuning knob for controlling synaptic device characteristics. By adopting a three-terminal transistor structure, the programming channel and reading channel are physically separated and the programming power consumption can be kept constantly low (∼50 pW) across a wide dynamic range of 105. This work demonstrates a complementary metal oxide semiconductor compatible approach to build power efficient synaptic devices for artificial intelligence applications.more » « less
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