Band alignment calculation of dielectric films on VO2

Zhang, Zhaofu; Chen, Jiaqi; Guo, Yuzheng; Robertson, John

doi:10.1016/j.mee.2019.111057

Cited by 4 publications

(3 citation statements)

References 40 publications

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“…The device shows pronounced phase change characteristic, shown in Figure e. Below the phase transition temperature ( T c ) the device exhibits semiconducting behavior with E gap = 565 meV band gap energy (see inset), which is in good agreement with the literature values. − By increasing the temperature the resistance drops suddenly at T c = 66.22 °C, while the device transforms to the low resistance metallic state. The resistance switching ratio between 30 and 100 °C exceeds 600.…”

Section: Resultssupporting

confidence: 83%

Interplay of Thermal and Electronic Effects in the Mott Transition of Nanosized VO₂ Phase Change Memory Devices

Pósa,

Hornung,

Török

et al. 2023

ACS Appl. Nano Mater.

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Volatile memory devices relying on the Mott-type insulator-to-metal transition of vanadium oxide (VO2) are widely utilized in the field of neuromorphic computing. Such devices, however, are realized in a nanoscale geometry, where the switching relies on the self-heating of an ultrasmall spot as well as the presence of extremely high electric fields in the active region. In this paper, we investigate the interplay of such nanoscale thermal and nonlinear electronic phenomena by investigating the temperature and voltage dependent conduction properties of our custom-designed VO2 devices, where a V-shaped electrode focuses the switching to an ultrasmall single-spot active region. This simplified spatial structure of the active volume facilitates the device modeling and the identification of physical mechanisms behind the phase transition. We find that purely thermal or electronic effects fail to describe the device operation, however, according to our finite element simulations, a combined electronic and thermal model provides a precise description of the device characteristics. These results facilitate the understanding as well as the thermal and electronic design of novel VO2-based neuronal devices.

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Section: Resultssupporting

confidence: 83%

Interplay of Thermal and Electronic Effects in the Mott Transition of Nanosized VO₂ Phase Change Memory Devices

Pósa,

Hornung,

Török

et al. 2023

ACS Appl. Nano Mater.

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“…Appropriate boundary conditions were chosen, and all the assumed parameters are shown in Table S1 (Supporting Information). 24,[44][45][46][47][60][61][62][63][64][65] While the simulation size of the device was much smaller than the actual device dimensions (10 nm thick and several micrometers long), it was found that the essential physical features observed in the experiments could be captured with this simulation system.…”

Section: Methodsmentioning

confidence: 99%

In‐Operando Spatiotemporal Imaging of Coupled Film‐Substrate Elastodynamics During an Insulator‐to‐Metal Transition

Stone,

Shi,

Jerry

et al. 2024

Advanced Materials

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The drive towards non‐von Neumann device architectures has led to an intense focus on insulator‐to‐metal (IMT) and the converse (MIT) transitions. Studies of electric field‐driven IMT in the prototypical VO2 thin‐film channel devices are largely focused on the electrical and elastic responses of the films, but the response of the corresponding TiO2 substrate is often overlooked since it is nominally expected to be electrically passive and elastically rigid. Here, in‐operando spatiotemporal imaging of the coupled elastodynamics using x‐ray diffraction microscopy of a VO2 film channel device on TiO2 substrate reveals two new surprises. First, the film channel bulges during the IMT, the opposite of the expected shrinking in the film undergoing IMT. Secondly, a microns thick proximal layer in the substrate also coherently bulges accompanying the IMT in the film, which is completely unexpected. Phase‐field simulations of coupled IMT, oxygen vacancy electronic dynamics, and electronic carrier diffusion incorporating thermal and strain effects suggest that the observed elastodynamics can be explained by the known naturally occurring oxygen vacancies that rapidly ionize (and deionize) in concert with the IMT (MIT). Fast electrical‐triggering of the IMT via ionizing defects and an active “IMT‐like” substrate layer are critical aspects to consider in device applications.This article is protected by copyright. All rights reserved

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“…b) Schematic positions of the valence band (VB) and conduction band (CB) relative to the Fermi level (E f ) for MO semiconductors and insulators, and MC semiconductors made by ALD techniques in previous reports. [ 32–47 ] The red dash line indicates the E f .…”

Section: Introductionmentioning

confidence: 99%

Atomic Layer Deposition of Metal Oxides and Chalcogenides for High Performance Transistors

et al. 2022

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Atomic layer deposition (ALD) is a deposition technique well‐suited to produce high‐quality thin film materials at the nanoscale for applications in transistors. This review comprehensively describes the latest developments in ALD of metal oxides (MOs) and chalcogenides with tunable bandgaps, compositions, and nanostructures for the fabrication of high‐performance field‐effect transistors. By ALD various n‐type and p‐type MOs, including binary and multinary semiconductors, can be deposited and applied as channel materials, transparent electrodes, or electrode interlayers for improving charge‐transport and switching properties of transistors. On the other hand, MO insulators by ALD are applied as dielectrics or protecting/encapsulating layers for enhancing device performance and stability. Metal chalcogenide semiconductors and their heterostructures made by ALD have shown great promise as novel building blocks to fabricate single channel or heterojunction materials in transistors. By correlating the device performance to the structural and chemical properties of the ALD materials, clear structure–property relations can be proposed, which can help to design better‐performing transistors. Finally, a brief concluding remark on these ALD materials and devices is presented, with insights into upcoming opportunities and challenges for future electronics and integrated applications.

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Band alignment calculation of dielectric films on VO2

Cited by 4 publications

References 40 publications

Interplay of Thermal and Electronic Effects in the Mott Transition of Nanosized VO₂ Phase Change Memory Devices

Interplay of Thermal and Electronic Effects in the Mott Transition of Nanosized VO₂ Phase Change Memory Devices

In‐Operando Spatiotemporal Imaging of Coupled Film‐Substrate Elastodynamics During an Insulator‐to‐Metal Transition

Atomic Layer Deposition of Metal Oxides and Chalcogenides for High Performance Transistors

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Band alignment calculation of dielectric films on VO2

Cited by 4 publications

References 40 publications

Interplay of Thermal and Electronic Effects in the Mott Transition of Nanosized VO2 Phase Change Memory Devices

Interplay of Thermal and Electronic Effects in the Mott Transition of Nanosized VO2 Phase Change Memory Devices

In‐Operando Spatiotemporal Imaging of Coupled Film‐Substrate Elastodynamics During an Insulator‐to‐Metal Transition

Atomic Layer Deposition of Metal Oxides and Chalcogenides for High Performance Transistors

Contact Info

Product

Resources

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Interplay of Thermal and Electronic Effects in the Mott Transition of Nanosized VO₂ Phase Change Memory Devices

Interplay of Thermal and Electronic Effects in the Mott Transition of Nanosized VO₂ Phase Change Memory Devices