| 1. |
- Chaika, Alexander N., et al.
(författare)
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Rotated domain network in graphene on cubic-SiC(001)
- 2014
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 25:13
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Tidskriftsartikel (refereegranskat)abstract
- The atomic structure of the cubic-SiC(001) surface during ultra-high vacuum graphene synthesis has been studied using scanning tunneling microscopy (STM) and low-energy electron diffraction. Atomically resolved STM studies prove the synthesis of a uniform, millimeter-scale graphene overlayer consisting of nanodomains rotated by +/- 13.5 degrees relative to the < 110 >-directed boundaries. The preferential directions of the domain boundaries coincide with the directions of carbon atomic chains on the SiC(001)-c(2 x 2) reconstruction, fabricated prior to graphene synthesis. The presented data show the correlation between the atomic structures of the SiC(001)-c(2 x 2) surface and the graphene/SiC(001) rotated domain network and pave the way for optimizing large-area graphene synthesis on low-cost cubic-SiC(001)/Si(001) wafers.
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| 2. |
- Wu, Han-Chun, et al.
(författare)
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Large positive in-plane magnetoresistance induced by localized states at nanodomain boundaries in graphene
- 2017
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Graphene supports long spin lifetimes and long diffusion lengths at room temperature, making it highly promising for spintronics. However, making graphene magnetic remains a principal challenge despite the many proposed solutions. Among these, graphene with zig-zag edges and ripples are the most promising candidates, as zig-zag edges are predicted to host spin-polarized electronic states, and spin-orbit coupling can be induced by ripples. Here we investigate the magnetoresistance of graphene grown on technologically relevant SiC/Si(001) wafers, where inherent nanodomain boundaries sandwich zig-zag structures between adjacent ripples of large curvature. Localized states at the nanodomain boundaries result in an unprecedented positive in-plane magnetoresistance with a strong temperature dependence. Our work may offer a tantalizing way to add the spin degree of freedom to graphene.
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| 3. |
- Wu, Han-Chun, et al.
(författare)
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Transport Gap Opening and High On-Off Current Ratio in Trilayer Graphene with Self-Aligned Nanodomain Boundaries.
- 2015
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-086X .- 1936-0851. ; 9:9, s. 8967-8975
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Tidskriftsartikel (refereegranskat)abstract
- Trilayer graphene exhibits exceptional electronic properties that are of interest both for fundamental science and for technological applications. The ability to achieve a high on-off current ratio is the central question in this field. Here, we propose a simple method to achieve a current on-off ratio of 10(4) by opening a transport gap in Bernal-stacked trilayer graphene. We synthesized Bernal-stacked trilayer graphene with self-aligned periodic nanodomain boundaries (NBs) on the technologically relevant vicinal cubic-SiC(001) substrate and performed electrical measurements. Our low-temperature transport measurements clearly demonstrate that the self-aligned periodic NBs can induce a charge transport gap greater than 1.3 eV. More remarkably, the transport gap of ∼0.4 eV persists even at 100 K. Our results show the feasibility of creating new electronic nanostructures with high on-off current ratios using graphene on cubic-SiC.
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| 4. |
- Babenkov, Sergey V., et al.
(författare)
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Hybrid organic-inorganic systems formed by self-assembled gold nanoparticles in CuPcF4 molecular crystal
- 2016
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Ingår i: Organic Electronics. - : Elsevier BV. - 1566-1199. ; 32, s. 228-236
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Tidskriftsartikel (refereegranskat)abstract
- In this work we have fabricated and studied hybrid organic-inorganic nanocomposite system formed by gold nanoparticles self-assembled in organic semiconductor thin film - copper tetrafluorophthalocyanine (CuPcF4). By means of Photoelectron Spectroscopy and Transmission Electron Microscopy (TEM) the evolution of the morphology and electronic structure of the system as a function of nominal gold content have been investigated. The gold atoms, deposited onto the CuPcF4 surface, diffuse into the organic matrix and self-assemble to nanoparticles in a well-defined manner with a narrow size distribution, which depends on the amount of deposited gold. Using High-Resolution TEM, we were able to observe the atomic planes of single gold nanoparticles and their coalescence processes. Photoelectron spectroscopy has not revealed any detectable chemical reaction between gold and organic. However, the strong upward band bending, induced by gold nanoparticles in the organic film, takes place.
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