講演情報
[21p-A311-2]Resistive switching behavior in nanoparticle atomic switch networks
〇(D)Oradee Srikimkaew1, Saverio Ricci2, Matteo Porzani2, Yusuke Nakaoka1, Daniele Ielmini2, Hirofumi Tanaka1,3 (1.LSSE, Kyushu Inst. Technol. (Kyutech), 2.POLI Milano, 3.Neuromorphic Center, Kyutech)
キーワード：
Nanoparticle Random Networks、Atomic Switch、Resistive Switching
Due to their intrinsic nonlinear dynamics, atomic switch networks (ASNs) have been proposed for implementing hardware-based reservoir computing (RC) systems. The nonlinear property of ASN devices is realized on the basis of resistive switching phenomena occurring between nanojunctions that link the whole network. Our group utilized the ASN consisting of Ag-Ag2S core-shell nanoparticles (NPs) as a physical reservoir for implementing material RC. In addition to circuit engineering, it is crucial to comprehend the source of reservoir property for enhancing the system. In this work, we investigated the resistive switching behavior of the Ag-Ag2S NPs-ASN by evaluating I-V characteristics. A planar Pt/Ag-Ag2>S NPs/Pt device was fabricated. The I−V curves of the device showed bipolar nonvolatile switching behavior. The device could switch between a state of high resistance (HRS) and low resistance (LRS) using a set voltage of approximately 0.8 V, and a reset voltage of -1.3 V. A compliance current (Icc) of 100 μA was utilized during the set operation to prevent electrical breakdown. The device exhibited a ratio of LRS-to-HRS up to ∼104. Such a high ratio suggests that the multilevel switching could be succeeded by altering Icc. To verify such a multilevel switching, I−V curves under different Icc were observed. The device showed nonvolatile switching with multiple current levels at Icc values of 10 μA, 100 μA, and 1 mA. In contrast, at the Icc of 1 μA, the device exhibited volatile switching behavior. Furthermore, I−V curves under different electrode gap sizes were also investigated. The result showed that the Icc of volatile-to-nonvolatile transformation increases when the gap size increase. In conclusion, we demonstrated that the Ag-Ag2S NPs-ASN exhibit multiple resistive switching modes, which can be tuned by altering the Icc or electrode gap size.