7 research outputs found

    Plasmonic properties of aluminium nanowires in amorphous silicon

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    Plasmonic structures can help enhance optical activity in the ultraviolet (UV) region and therefore enhancing photocatalytic reactions and the detection of organic and biological species. Most plasmonic structures are composed of Ag or Au. However, producing structures small enough for optical activity in the UV region has proved difficult. In this study, we demonstrate that aluminium nanowires are an excellent alternative. We investigated the plasmonic properties of the Al nanowires as well as the optoelectronic properties of the surrounding a − Si matrix by combining scanning transmission electron microscopy imaging, electron energy loss spectroscopy and electrodynamic modelling. We have found that the Al nanowires have distinct plasmonic modes in the UV and far UV region, from 0.75 eV to 13 eV. In addition, simulated results found that the size and spacing of the Al nanowires, as well as the embedding material were shown to have a large impact on the type of surface plasmon energies that can be generated in the material. Using electromagnetic modelling, we have identified the modes and illustrated how they could be tuned further.publishedVersio

    Galvanic restructuring of exsolved nanoparticles for plasmonic and electrocatalytic energy conversion

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    There is a growing need to control and tune nanoparticles (NPs) to increase their stability and effectiveness, especially for photo‐ and electrochemical energy conversion applications. Exsolved particles are well anchored and can be re‐shaped without changing their initial location and structural arrangement. However, this usually involves lengthy treatments and use of toxic gases. Here, the galvanic replacement/deposition method is used, which is simpler, safer, and leads to a wealth of new hybrid nanostructures with a higher degree of tailorability. The produced NiAu bimetallic nanostructures supported on SrTiO3 display exceptional activity in plasmon‐assisted photoelectrochemical (PEC) water oxidation reactions. In situ scanning transmission electron microscopy is used to visualize the structural evolution of the plasmonic bimetallic structures, while theoretical simulations provide mechanistic insight and correlate the surface plasmon resonance effects with structural features and enhanced PEC performance. The versatility of this concept in shifting catalytic modes to the hydrogen evolution reaction is demonstrated by preparing hybrid NiPt bimetallic NPs of low Pt loadings on highly reduced SrTiO3 supports. This powerful methodology enables the design of supported bimetallic nanomaterials with tunable morphology and catalytic functionalities through minimal engineering

    Plasmonic properties of aluminium nanowires in amorphous silicon

    Get PDF
    Plasmonic structures can help enhance optical activity in the ultraviolet (UV) region and therefore enhancing photocatalytic reactions and the detection of organic and biological species. Most plasmonic structures are composed of Ag or Au. However, producing structures small enough for optical activity in the UV region has proved difficult. In this study, we demonstrate that aluminium nanowires are an excellent alternative. We investigated the plasmonic properties of the Al nanowires as well as the optoelectronic properties of the surrounding aSi matrix by combining scanning transmission electron microscopy (STEM) imaging, electron energy loss spectroscopy (EELS) and electrodynamic modelling. We have found that the Al nanowires have distinct plasmonic modes in the UV and far UV region, from 0.75 eV to 13 eV. In addition, the size and spacing of the Al nanowires, as well as the embedding material were shown to have a large impact on the type of surface plasmons energies that can be generated in the material. Using electromagnetic modelling, we have identified the modes and illustrated how they could be tuned further

    Germline HOXB13 mutations p.G84E and p.R217C do not confer an increased breast cancer risk

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    In breast cancer, high levels of homeobox protein Hox-B13 (HOXB13) have been associated with disease progression of ER-positive breast cancer patients and resistance to tamoxifen treatment. Since HOXB13 p.G84E is a prostate cancer risk allele, we evaluated the association between HOXB13 germline mutations and breast cancer risk in a previous study consisting of 3,270 familial non-BRCA1/2 breast cancer cases and 2,327 controls from the Netherlands. Although both recurrent HOXB13 mutations p.G84E and p.R217C were not associated with breast cancer risk, the risk estimation for p.R217C was not very precise. To provide more conclusive evidence regarding the role of HOXB13 in breast cancer susceptibility, we here evaluated the association between HOXB13 mutations and increased breast cancer risk within 81 studies of the international Breast Cancer Association Consortium containing 68,521 invasive breast cancer patients and 54,865 controls. Both HOXB13 p.G84E and p.R217C did not associate with the development of breast cancer in European women, neither in the overall analysis (OR = 1.035, 95% CI = 0.859-1.246, P = 0.718 and OR = 0.798, 95% CI = 0.482-1.322, P = 0.381 respectively), nor in specific high-risk subgroups or breast cancer subtypes. Thus, although involved in breast cancer progression, HOXB13 is not a material breast cancer susceptibility gene.Peer reviewe

    Anisotropic and trap-limited diffusion of hydrogen/deuterium in monoclinic gallium oxide single crystals

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    The effect of lattice anisotropy on the diffusion of hydrogen (H)/deuterium (2H) in β-Ga2O3 was investigated using secondary ion mass spectrometry (SIMS) and hybrid-functional calculations. Concentration-depth profiles of 2H-implanted single crystals show that 2H can diffuse along the direction perpendicular to the (010) surface at temperatures as low as 300 °C, whereas diffusion along the direction perpendicular to the (-201) surface occurs only around 500 °C. For both directions, the evolution of the 2H concentration–depth profiles after heat treatments can be modeled by trap-limited diffusion. Moreover, the traps can be present in the as-received crystals or created during ion implantation. Comparison of the experimentally obtained binding energy for 2H to the trap (2.3 ± 0.2 eV) with the binding energies determined from first-principles calculations suggests that intrinsic point defects (e.g., VibGa) or defect complexes (e.g., VGa(2)VO(2)) are excellent candidates for the trap and will play a crucial role in the diffusion of H or 2H in β-Ga2O3
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