Nonvolatile Resistive Switching in Nanocrystalline Molybdenum Disulfide with Ion‐Based Plasticity

Abstract

Non‐volatile resistive switching is demonstrated in memristors with nanocrystalline molybdenum disulfide (MoS2) as the active material. The vertical heterostructures consist of silicon (Si), vertically aligned MoS2, and chrome/gold metal electrodes. Electrical characterizations reveal a bipolar and forming‐free switching process with stable retention for at least 2500 s. Controlled experiments carried out in ambient and vacuum conditions suggest that the observed resistive switching is based on hydroxyl ions (OH−). These originate from catalytic splitting of adsorbed water molecules by MoS2. Experimental results in combination with analytical simulations further suggest that electric field driven movement of the mobile OH− ions along the vertical MoS2 layers influences the energy barrier at the Si/MoS2 interface. The scalable and semiconductor production compatible device fabrication process used in this work offers the opportunity to integrate such memristors into existing Si technology for future neuromorphic applications. The observed ion‐based plasticity may be exploited in ionic‐electronic devices based on transition metal dichalcogenides and other 2D materials for memristive applications.

Electron Transport across Vertical Silicon/MoS2/Graphene Heterostructures: Towards Efficient Emitter Diodes for Graphene Base Hot Electron Transistors

“…This is in the range of the flat-band voltage (V FB ) shift due to the negative charges in the MoS 2 bulk as observed in our earlier work. 27,50,51 It is worth noting here that, for a nonhomogeneous charge distribution across the SSG structure (Figure 2c), the electric field at the Si/MoS 2 interface differs considerably from V/d. As demonstrated in Figure 6b,c, the negative charges in MoS 2 induce a barrier (EB2) whose maximum point gradually shifts toward the Si/MoS 2 interface for increasing applied voltage.…”

Large-area integration of two-dimensional materials and their heterostructures by wafer bonding

“…For graphene, an atomically thin layer of carbon atoms, the ultrahigh charge carrier mobility, and its strong light absorption enabled the demonstration of high-frequency analog electronics 1 , 2 , flexible electronics 3 , high-sensitivity Hall sensors 4 , 5 , and high-speed photodetectors for telecommunication and imaging technologies 6 – 8 . Transition metal dichalcogenides are often semiconducting and promise advancements for high- and low-power transistors 9 , infrared photodetectors 10 , and emerging device concepts such as memristors 11 – 13 and single-photon emitters for optical quantum communication 14 – 16 . The scaling limit of transistors is set by short-channel effects that arise from intrinsic semiconductor properties.…”

Highly Responsive Flexible Photodetectors Based on MOVPE Grown Uniform Few-Layer MoS2

“…The TAC process requires very high homogeneity of the sputtered or evaporated metal film and bears the risk of unsulfurized regions for thicker films. CVD and TAC films may have a nanocrystalline character , or a vertical layer orientation . Metal–organic vapor phase epitaxy (MOVPE) can overcome these issues by providing superior reproducibility, film homogeneity, and scalability, which are required for electronic devices, as shown for the growth of TMDCs like WS 2 and MoS 2 …”

“…CVD and TAC films may have a nanocrystalline character 25,26 or a vertical layer orientation. 27 Metal−organic vapor phase epitaxy (MOVPE) can overcome these issues by providing superior reproducibility, film homogeneity, and scalability, which are required for electronic devices, as shown for the growth of TMDCs like WS 2 28 and MoS 2 . In this work, we demonstrate high-responsivity metal− semiconductor−metal (MSM) photodetectors with gatetunable sensitivity based on few-layer (FL) MoS 2 .…”