The Experts below are selected from a list of 269373 Experts worldwide ranked by ideXlab platform
Falko P. Netzer - One of the best experts on this subject based on the ideXlab platform.
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Vanadium Oxide Surface studies
Progress in Surface Science, 2003Co-Authors: Svetlozar Surnev, M.g. Ramsey, Falko P. NetzerAbstract:Abstract The vanadium Oxides can exist in a range of single and mixed valencies with a large variety of structures. The large diversity of physical and chemical properties that they can thus possess make them technologically important and a rich ground for basic research. Here we assess the present status of the microscopic understanding of the physico-chemical properties of vanadium Oxide Surfaces. The discussion is restricted to atomically well-defined systems as probed by Surface techniques. Following a brief review of the properties of the bulk Oxides the electronic and geometric structure of their clean single crystal Surfaces and adsorption studies, probing their chemical reactivity, are considered. The review then focuses on the growth and the Surface properties of vanadium Oxide thin films. This is partitioned into films grown on Oxide substrates and those on metal substrates. The interest in the former derives from their importance as supported metal Oxide catalysts and the need to understand the two-dimensional overlayer of the so-called “monolayer” catalyst. On the single crystal metal substrates thin Oxide layers with high structural order and interesting properties can be prepared. Particular attention is given to ultrathin vanadium Oxide layers, so-called nano-layers, where novel phases, stabilised by the substrate, form.
Guosheng Fang - One of the best experts on this subject based on the ideXlab platform.
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A Mössbauer study of spin-pinning in the Oxide Surface layer on fine iron particles
Hyperfine Interactions, 1992Co-Authors: Runsheng Huang, Hongqi Xiong, Yuanfu Hsia, Rongchuan Liu, Lianwei Wang, Guosheng FangAbstract:Fine α-Fe particles coated with an Oxide Surface layer were prepared by the evaporation technique. The spin pinning in the Oxide Surface layer were studied by means of the Mossbauer effect in an applied field of 6T during a thermal-cycle process. The anisotropy energy on the Surface was estimated.
Pavel B Paramonov - One of the best experts on this subject based on the ideXlab platform.
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theoretical characterization of the indium tin Oxide Surface and of its binding sites for adsorption of phosphonic acid monolayers
Chemistry of Materials, 2008Co-Authors: Pavel B Paramonov, Sergio A Paniagua, Peter J Hotchkiss, Simon C Jones, Neal R Armstrong, Seth R Marder, Jeanluc BredasAbstract:We present a theoretical characterization, based on density functional theory, of the indium tin Oxide Surface and of the nature of the binding sites that determine the adsorption of phosphonic acid monolayers. The validity of our theoretical description is assessed by comparing our first-principles results to X-ray photoelectron spectroscopy data.
James Ullock - One of the best experts on this subject based on the ideXlab platform.
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zirconium Oxide Surface passivation of crystalline silicon
Applied Physics Letters, 2018Co-Authors: James Ullock, Mark Hettick, Ju Peng, Ali Javey, Andres CuevasAbstract:This letter reports effective passivation of crystalline silicon (c-Si) Surfaces by thermal atomic layer deposited zirconium Oxide (ZrOx). The optimum layer thickness and activation annealing conditions are determined to be 20 nm and 300 °C for 20 min. Cross-sectional transmission electron microscopy imaging shows an approximately 1.6 nm thick SiOx interfacial layer underneath an 18 nm ZrOx layer, consistent with ellipsometry measurements (∼20 nm). Capacitance–voltage measurements show that the annealed ZrOx film features a low interface defect density of 1.0 × 1011 cm−2 eV−1 and a low negative film charge density of −6 × 1010 cm−2. Effective lifetimes of 673 μs and 1.1 ms are achieved on p-type and n-type 1 Ω cm undiffused c-Si wafers, respectively, corresponding to an implied open circuit voltage above 720 mV in both cases. The results demonstrate that Surface passivation quality provided by ALD ZrOx is consistent with the requirements of high efficiency silicon solar cells.This letter reports effective passivation of crystalline silicon (c-Si) Surfaces by thermal atomic layer deposited zirconium Oxide (ZrOx). The optimum layer thickness and activation annealing conditions are determined to be 20 nm and 300 °C for 20 min. Cross-sectional transmission electron microscopy imaging shows an approximately 1.6 nm thick SiOx interfacial layer underneath an 18 nm ZrOx layer, consistent with ellipsometry measurements (∼20 nm). Capacitance–voltage measurements show that the annealed ZrOx film features a low interface defect density of 1.0 × 1011 cm−2 eV−1 and a low negative film charge density of −6 × 1010 cm−2. Effective lifetimes of 673 μs and 1.1 ms are achieved on p-type and n-type 1 Ω cm undiffused c-Si wafers, respectively, corresponding to an implied open circuit voltage above 720 mV in both cases. The results demonstrate that Surface passivation quality provided by ALD ZrOx is consistent with the requirements of high efficiency silicon solar cells.
Svetlozar Surnev - One of the best experts on this subject based on the ideXlab platform.
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Vanadium Oxide Surface studies
Progress in Surface Science, 2003Co-Authors: Svetlozar Surnev, M.g. Ramsey, Falko P. NetzerAbstract:Abstract The vanadium Oxides can exist in a range of single and mixed valencies with a large variety of structures. The large diversity of physical and chemical properties that they can thus possess make them technologically important and a rich ground for basic research. Here we assess the present status of the microscopic understanding of the physico-chemical properties of vanadium Oxide Surfaces. The discussion is restricted to atomically well-defined systems as probed by Surface techniques. Following a brief review of the properties of the bulk Oxides the electronic and geometric structure of their clean single crystal Surfaces and adsorption studies, probing their chemical reactivity, are considered. The review then focuses on the growth and the Surface properties of vanadium Oxide thin films. This is partitioned into films grown on Oxide substrates and those on metal substrates. The interest in the former derives from their importance as supported metal Oxide catalysts and the need to understand the two-dimensional overlayer of the so-called “monolayer” catalyst. On the single crystal metal substrates thin Oxide layers with high structural order and interesting properties can be prepared. Particular attention is given to ultrathin vanadium Oxide layers, so-called nano-layers, where novel phases, stabilised by the substrate, form.
