The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform
Allan Matthews - One of the best experts on this subject based on the ideXlab platform.
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a new approach to the deposition of Elemental Boron and Boron based coatings by pulsed magnetron sputtering of loosely packed Boron powder targets
Plasma Processes and Polymers, 2007Co-Authors: M. Audronis, Adrian Leyland, P J Kelly, Allan MatthewsAbstract:Large numbers of potential application areas for Elemental Boron and Boron-based thin film materials make this subject area a focus of significant scientific and industrial interest. Applications include thermoelectric energy conversion devices, biomedical implants, metalworking tools and automotive components. Boron is however also recognised widely to be a difficult-to-deposit material. Therefore, a new technique to deposit Boron (and other Boron-based materials) by pulsed magnetron sputtering of loosely packed powder targets has been proposed. Among the benefits of this approach are: improved stability of the deposition process, increased speed and flexibility of target preparation, enhanced time- and cost-effectiveness and the ability to control readily the target and hence the chemical composition of the coating.
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A New Approach to the Deposition of Elemental Boron and Boron‐Based Coatings by Pulsed Magnetron Sputtering of Loosely Packed Boron Powder Targets
Plasma Processes and Polymers, 2007Co-Authors: M. Audronis, Peter Kelly, Adrian Leyland, Allan MatthewsAbstract:Large numbers of potential application areas for Elemental Boron and Boron-based thin film materials make this subject area a focus of significant scientific and industrial interest. Applications include thermoelectric energy conversion devices, biomedical implants, metalworking tools and automotive components. Boron is however also recognised widely to be a difficult-to-deposit material. Therefore, a new technique to deposit Boron (and other Boron-based materials) by pulsed magnetron sputtering of loosely packed powder targets has been proposed. Among the benefits of this approach are: improved stability of the deposition process, increased speed and flexibility of target preparation, enhanced time- and cost-effectiveness and the ability to control readily the target and hence the chemical composition of the coating.
M. L. Huberman - One of the best experts on this subject based on the ideXlab platform.
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Elemental Boron‐doped p+‐SiGe layers grown by molecular beam epitaxy for infrared detector applications
Applied Physics Letters, 1992Co-Authors: T. L. Lin, T. George, E. W. Jones, A. Ksendzov, M. L. HubermanAbstract:SiGe/Si heterojunction internal photoemission (HIP) detectors have been fabricated utilizing molecular beam epitaxy of p+‐SiGe layers on p−‐Si substrates. Elemental Boron from a high‐temperature effusion cell was used as the dopant source during molecular beam epitaxy (MBE) growth, and high doping concentrations (≳5×1020 cm−3) have been achieved. Strong infrared absorption, mainly by free‐carrier absorption, was observed for the degenerately doped SiGe layers. The use of Elemental Boron as the dopant source allows a low MBE growth temperature (350 °C), resulting in improved crystalline quality and smooth surface morphology of the Si0.7Ge0.3 layers. Nearly ideal thermionic emission dark current characteristics have been obtained. Photoresponse of the HIP detectors in the long‐wavelength infrared regime has been demonstrated.
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Elemental Boron doped p sige layers grown by molecular beam epitaxy for infrared detector applications
Applied Physics Letters, 1992Co-Authors: T. L. Lin, T. George, E. W. Jones, A. Ksendzov, M. L. HubermanAbstract:SiGe/Si heterojunction internal photoemission (HIP) detectors have been fabricated utilizing molecular beam epitaxy of p+‐SiGe layers on p−‐Si substrates. Elemental Boron from a high‐temperature effusion cell was used as the dopant source during molecular beam epitaxy (MBE) growth, and high doping concentrations (≳5×1020 cm−3) have been achieved. Strong infrared absorption, mainly by free‐carrier absorption, was observed for the degenerately doped SiGe layers. The use of Elemental Boron as the dopant source allows a low MBE growth temperature (350 °C), resulting in improved crystalline quality and smooth surface morphology of the Si0.7Ge0.3 layers. Nearly ideal thermionic emission dark current characteristics have been obtained. Photoresponse of the HIP detectors in the long‐wavelength infrared regime has been demonstrated.
Wai-yim Ching - One of the best experts on this subject based on the ideXlab platform.
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spectroscopic properties of crystalline Elemental Boron and the implications on b11c cbc
RSC Advances, 2013Co-Authors: Liaoyuan Wang, Paul Rulis, Wai-yim ChingAbstract:Elemental Boron is a complicated material that involves a variety of phases with puzzling structures that are still controversial to this day. The allotropes of solid Elemental Boron include six crystalline phases (α-rhombohedral, β-rhombohedral, α-tetragonal, β-tetragonal, γ-orthorhombic, and α-Ga type), amorphous phases, and nanoscale structures. In the present work, the electronic structure and spectroscopic properties [X-ray absorption near edge structure (XANES) and optical dielectric functions] of the six crystalline phases were studied via the ab initio orthogonalized linear combination of atomic orbitals (OLCAO) method. The calculated XANES and dielectric functions of the α- and β-rhombohedral phases agree well with experiment. Based on this agreement, we predict the XANES spectra and dielectric functions for the other four crystalline phases. Each of the calculated XANES spectra of the five phases that have icosahedral units or clusters of icosahedra show a characteristic set of peak features in the energy range from 190 to 215 eV. These characteristic features were also observed in the XANES spectra of the icosahedron-containing B11C–CBC, a typical Boron-rich compound.
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Spectroscopic properties of crystalline Elemental Boron and the implications on B11C–CBC
RSC Advances, 2013Co-Authors: Liaoyuan Wang, Paul Rulis, Wai-yim ChingAbstract:Elemental Boron is a complicated material that involves a variety of phases with puzzling structures that are still controversial to this day. The allotropes of solid Elemental Boron include six crystalline phases (α-rhombohedral, β-rhombohedral, α-tetragonal, β-tetragonal, γ-orthorhombic, and α-Ga type), amorphous phases, and nanoscale structures. In the present work, the electronic structure and spectroscopic properties [X-ray absorption near edge structure (XANES) and optical dielectric functions] of the six crystalline phases were studied via the ab initio orthogonalized linear combination of atomic orbitals (OLCAO) method. The calculated XANES and dielectric functions of the α- and β-rhombohedral phases agree well with experiment. Based on this agreement, we predict the XANES spectra and dielectric functions for the other four crystalline phases. Each of the calculated XANES spectra of the five phases that have icosahedral units or clusters of icosahedra show a characteristic set of peak features in the energy range from 190 to 215 eV. These characteristic features were also observed in the XANES spectra of the icosahedron-containing B11C–CBC, a typical Boron-rich compound.
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Spectral analysis of the electronic structure of γ-B28
Journal of Superhard Materials, 2011Co-Authors: P. Rulis, Liaoyuan Wang, B. Walker, Wai-yim ChingAbstract:Elemental Boron and Boron-rich compounds have been the subjects of intense theoretical and practical interest and seem to be surrounded by an almost unceasing controversy with respect to their fundamental atomic and electronic structures. The sensitivity of Boron to the presence of impurities leads to exceptional difficulty in preparing material samples of a specific purity or stoichiometry. Hence, the detailed effort to map out and understand the atomic and electronic structures of these materials, which has been painstakingly performed by numerous researchers over many decades, has often been fraught with missteps. However, when a theoretical or experimental method finally has proven to be successful in dealing with Boron and its compounds it is often heralded as a triumph of science and is thus linked with the development of a deeper and more fundamental understanding of the physics of atomic interaction. This focused review article provides an analysis of the current state of understanding the atomic and electronic structures of Elemental Boron and Boron-rich compounds with a strong bent towards the parts of the story related to the γ-B28 modification of pure Boron. Also, while many techniques have been instrument-al, the focus here will be on the results obtained from experimental and theoretical/computational methods of core level spectroscopy.
M. Audronis - One of the best experts on this subject based on the ideXlab platform.
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a new approach to the deposition of Elemental Boron and Boron based coatings by pulsed magnetron sputtering of loosely packed Boron powder targets
Plasma Processes and Polymers, 2007Co-Authors: M. Audronis, Adrian Leyland, P J Kelly, Allan MatthewsAbstract:Large numbers of potential application areas for Elemental Boron and Boron-based thin film materials make this subject area a focus of significant scientific and industrial interest. Applications include thermoelectric energy conversion devices, biomedical implants, metalworking tools and automotive components. Boron is however also recognised widely to be a difficult-to-deposit material. Therefore, a new technique to deposit Boron (and other Boron-based materials) by pulsed magnetron sputtering of loosely packed powder targets has been proposed. Among the benefits of this approach are: improved stability of the deposition process, increased speed and flexibility of target preparation, enhanced time- and cost-effectiveness and the ability to control readily the target and hence the chemical composition of the coating.
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A New Approach to the Deposition of Elemental Boron and Boron‐Based Coatings by Pulsed Magnetron Sputtering of Loosely Packed Boron Powder Targets
Plasma Processes and Polymers, 2007Co-Authors: M. Audronis, Peter Kelly, Adrian Leyland, Allan MatthewsAbstract:Large numbers of potential application areas for Elemental Boron and Boron-based thin film materials make this subject area a focus of significant scientific and industrial interest. Applications include thermoelectric energy conversion devices, biomedical implants, metalworking tools and automotive components. Boron is however also recognised widely to be a difficult-to-deposit material. Therefore, a new technique to deposit Boron (and other Boron-based materials) by pulsed magnetron sputtering of loosely packed powder targets has been proposed. Among the benefits of this approach are: improved stability of the deposition process, increased speed and flexibility of target preparation, enhanced time- and cost-effectiveness and the ability to control readily the target and hence the chemical composition of the coating.
T. L. Lin - One of the best experts on this subject based on the ideXlab platform.
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Elemental Boron‐doped p+‐SiGe layers grown by molecular beam epitaxy for infrared detector applications
Applied Physics Letters, 1992Co-Authors: T. L. Lin, T. George, E. W. Jones, A. Ksendzov, M. L. HubermanAbstract:SiGe/Si heterojunction internal photoemission (HIP) detectors have been fabricated utilizing molecular beam epitaxy of p+‐SiGe layers on p−‐Si substrates. Elemental Boron from a high‐temperature effusion cell was used as the dopant source during molecular beam epitaxy (MBE) growth, and high doping concentrations (≳5×1020 cm−3) have been achieved. Strong infrared absorption, mainly by free‐carrier absorption, was observed for the degenerately doped SiGe layers. The use of Elemental Boron as the dopant source allows a low MBE growth temperature (350 °C), resulting in improved crystalline quality and smooth surface morphology of the Si0.7Ge0.3 layers. Nearly ideal thermionic emission dark current characteristics have been obtained. Photoresponse of the HIP detectors in the long‐wavelength infrared regime has been demonstrated.
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Elemental Boron doped p sige layers grown by molecular beam epitaxy for infrared detector applications
Applied Physics Letters, 1992Co-Authors: T. L. Lin, T. George, E. W. Jones, A. Ksendzov, M. L. HubermanAbstract:SiGe/Si heterojunction internal photoemission (HIP) detectors have been fabricated utilizing molecular beam epitaxy of p+‐SiGe layers on p−‐Si substrates. Elemental Boron from a high‐temperature effusion cell was used as the dopant source during molecular beam epitaxy (MBE) growth, and high doping concentrations (≳5×1020 cm−3) have been achieved. Strong infrared absorption, mainly by free‐carrier absorption, was observed for the degenerately doped SiGe layers. The use of Elemental Boron as the dopant source allows a low MBE growth temperature (350 °C), resulting in improved crystalline quality and smooth surface morphology of the Si0.7Ge0.3 layers. Nearly ideal thermionic emission dark current characteristics have been obtained. Photoresponse of the HIP detectors in the long‐wavelength infrared regime has been demonstrated.