Fabrication of an electrical spin transport device utilizing a diazonium salt/hafnium oxide interface layer on epitaxial graphene grown on 6 H-SiC(0001)

AbstractGroup III-V semiconductor materials are being studied as potential replacements for conventional CMOS technology due to their better electron transport properties. However, the excess scattering of carriers in MOSFET channel due to high-k gate oxide interface significantly depreciates the benefits of III-V high-mobility channel materials. We present results on Hall electron mobility of buried QW structures influenced by remote scattering due to InGaAs/HfO2 interface. Mobility in In0.77Ga0.23As QWs degraded from 12000 to 1200 cm2/V-s and the mobility vs. temperature slope changed from T-1.2 to almost T+1.0 in 77-300 K range when the barrier thickness is reduced from 50 to 0 nm. This mobility change is attributed to remote Coulomb scattering due to charges and dipoles at semiconductor/oxide interface. Elimination of the InGaAs/HfO2 interface via introduction of SiOx interface layer formed by oxidation of thin a-Si passivation layer was found to improve the channel mobility. The mobility vs. sheet carrier density shows the maximum close to 2×1012 cm-2.

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Spin transport in epitaxial graphene on the C-terminated ( 0001¯)-face of silicon carbide

Applied Physics Letters ◽

10.1063/1.4955017 ◽

2016 ◽

Vol 109 (1) ◽

pp. 012402 ◽

Cited By ~ 4

Author(s):

J. J. van den Berg ◽

R. Yakimova ◽

B. J. van Wees

Keyword(s):

Silicon Carbide ◽

Spin Transport ◽

Epitaxial Graphene

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Surface Transport Properties of Pb-Intercalated Graphene

Materials ◽

10.3390/ma14247706 ◽

2021 ◽

Vol 14 (24) ◽

pp. 7706

Author(s):

Markus Gruschwitz ◽

Chitran Ghosal ◽

Ting-Hsuan Shen ◽

Susanne Wolff ◽

Thomas Seyller ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Surface Defects ◽

Interface Layer ◽

Epitaxial Graphene ◽

Buffer Layers ◽

Scanning Tunneling ◽

Large Area ◽

Tunneling Microscopy ◽

Surface Transport ◽

Static Distortion

Intercalation experiments on epitaxial graphene are attracting a lot of attention at present as a tool to further boost the electronic properties of 2D graphene. In this work, we studied the intercalation of Pb using buffer layers on 6H-SiC(0001) by means of electron diffraction, scanning tunneling microscopy, photoelectron spectroscopy and in situ surface transport. Large-area intercalation of a few Pb monolayers succeeded via surface defects. The intercalated Pb forms a characteristic striped phase and leads to formation of almost charge neutral graphene in proximity to a Pb layer. The Pb intercalated layer consists of 2 ML and shows a strong structural corrugation. The epitaxial heterostructure provides an extremely high conductivity of σ=100 mS/□. However, at low temperatures (70 K), we found a metal-insulator transition that we assign to the formation of minigaps in epitaxial graphene, possibly induced by a static distortion of graphene following the corrugation of the interface layer.

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Influence of Hybrid Sol-Gel Crosslinker on Self-Healing Properties for Multifunctional Coatings

Materials ◽

10.3390/ma14185382 ◽

2021 ◽

Vol 14 (18) ◽

pp. 5382

Author(s):

Guillaume Lollivier ◽

Marie Gressier ◽

Florence Ansart ◽

Maëlenn Aufray ◽

Marie-Joëlle Menu

Keyword(s):

Sol Gel ◽

Interface Layer ◽

Hybrid Coatings ◽

Organic Polymer ◽

Self Healing ◽

Oxide Interface ◽

Protective Oxide ◽

New Class ◽

One Step

Self-healing polymers are a new class of material that has recently received a lot of attention because of the lifespan improvement it could bring to multiple applications. One of the major challenges is to obtain multifunctional materials which can self-heal and exhibit other interesting properties such as protection against corrosion. In this paper, the effect of the incorporation of an aminosilane on the properties of a self-healing organic polymer containing disulfide bond is studied on films and coatings for aluminium AA2024-T3 using simple one step in situ synthesis. Hybrid coatings with enhanced anticorrosion properties measured by EIS were obtained thanks to the formation of a protective oxide interface layer, while exhibiting wound closure after exposition at 75 °C. The thermal, mechanical and rheological properties of the films with different aminosilane amounts were characterized in order to understand the influence of the slight presence of the inorganic network. Stiffer and reprocessable hybrid films were obtained, capable to recover their mechanical properties after healing. The nanocomposite structure, confirmed by TEM, had a positive effect on the self-healing and stress relaxation properties. These results highlight the potential of sol-gel chemistry to obtain efficient anticorrosion and self-healing coatings.

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