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Creator | Title | Description | Subject | Date |
251 |
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Scarpulla, Michael | Synthesis and properties of highly mismatched II-O-I alloys | Ternary and quaternary dilute II-VI oxides were synthesised using a highly nonequilibrium method: the combination of O ion implantation and pulsed-laser melting. CdOxTe12x thin films have been produced with x up to 0.015 and with the energy gap reduced by 0.15 eV. Optical transitions corresponding t... | Highly mismatched alloys; Cadmium telluride; Zinc telluride; Anticrossing | 2004 |
252 |
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Scarpulla, Michael | Synthesis of GaNxAs1-x thin films by pulsed laser melting and rapid thermal annealing of N+-implanted GaAs | We present a systematic investigation on the formation of the highly mismatched alloy GaNxAs1-x using N1-implantation followed by a combination of pulsed laser melting and rapid thermal annealing. Thin films of GaNxAs1-x with x as high as 0.016 and an activation efficiency of the implanted N up to 5... | Highly mismatched alloys; Gallium arsenide | 2003 |
253 |
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Tiwari, Ashutosh | Tb2O3 thin films: An alternative candidate for high-k dielectric applications | We are reporting the growth and structural, optical, and dielectric properties of Tb2O3, a relatively unexplored high-k dielectric material. A pulsed-laser deposition technique was used to grow Tb2O3 thin-films on four different substrates: Si(100), SrTiO3(100), LaAlO3(100), and MgO(100). High resol... | | 2014-01-01 |
254 |
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Stringfellow, Gerald B. | Te doping of GaInP: ordering and step structure | The donor Te has been added to GaInP during organometallic vapor phase epitaxial growth using the precursor diethyltelluride. In agreement with previous studies, the addition of high Te concentrations leads to the elimination of the CuPt ordering observed in undoped layers. The degree of order is es... | Epitaxial growth; Heterostructures; Growth parameters | 1999-04-01 |
255 |
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Scarpulla, Michael | Te-rich CdTe surface by pulsed UV laser treatment for ohmic back contact formation | Pulsed UV laser treatments have recently been applied to polycrystalline CdTe solar cells to create an ohmic back contact. In this work, we investigate the surface stoichiometry variations produced by pulsed laser excitation using X-ray photoelectron spectroscopy (XPS). These results reveal surfaces... | | 2014-01-01 |
256 |
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Scarpulla, Michael | Temperature dependence of equivalent circuit parameters used to analyze admittance spectroscopy and application to CZTSe devices | We present a device physics and equivalent circuit model for admittance spectroscopy of CZTSe based photovoltaic devices. The experimental variations of the capacitance and conductance in the depletion width are reproduced for state of the art coevaporated CZTSe devices. We will show that simple Arr... | | 2014-01-01 |
257 |
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Scarpulla, Michael | Temperature dependent conductivity of polycrystalline Cu 2ZnSnS 4 thin films | The temperature-dependent conductivity of Cu2ZnSnS4 (CZTS) thin films prepared by sulfurization of different sputtered ZnS/Cu/Sn stacks and also of the same stack annealed for different times was investigated from 30-300 K. Fitting of the through-thickness conductivity requires a model including Mot... | | 2012-01-01 |
258 |
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Bedrov, Dmitro; Smith, Grant D. | Temperature dependent shear viscosity coefficient of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX ): a molecular dynamics simulation study | Equilibrium molecular dynamics methods were used in conjunction with linear response theory and a recently published potential-energy surface [J. Phys. Chem. B 103, 3570 (1999)] to compute the liquid shear viscosity and self-diffusion coefficient of the high explosive HMX (octahydro-1,3,5,7-tetran... | Polymer melts; HMX; Shear viscosity coefficient; Plastic-bonded explosives | 2000 |
259 |
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Stringfellow, Gerald B. | Tertiarybutyldimethylantimony: a new Sb source for low temperature organometallic vapor phase epitaxial growth of InSb | This article investigates tertiarybutyldimethylantimony as a source for low-temperature organometallic vapor phase epitaxial growth of indium antimonide (InSB); extraction of good surface morphology InSb layers; efficiency of InSB growth; and, presence of a negligible parasitic reaction between trim... | Tertiarybutyldimethylantimony; Indium antimonide crystals | 1992 |
260 |
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Liu, Feng | Theory of directed nucleation of strained islands on patterned substrates | We develop a theoretical model to elucidate the nucleation of strained islands on patterned substrates. We show that island nucleation is directed to the preferred sites by a much lower energy barrier and smaller critical size. Strain relaxation directs island nucleation to the bottom of a pit rat... | Directed nucleation; Strained islands; Patterned substrates | 2008-11 |
261 |
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Liu, Feng | Theory of equilibrium shape of an anisotropically strained island: thermodynamic limits for growth of nanowires | Using continuum elastic theory, we show that strain anisotropy removes the shape instability existing for an isotropically strained island. An anistropically strained island has always an anisotropic shape, elongating along the less-strained direction and adopting a narrow width in the more-strain... | Strained islands; Equilibrium shape; Growth; Thermodynamic limits | 2004-11 |
262 |
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Liu, Feng | Theory of hydrogen pairing in yttrium | The energetics of hydrogen atoms interacting with yttrium have been investigated using the self-consistent cluster model and the local-density approximation. Our results provide a theoretical understanding of a range of novel phenomena observed recently in resistivity, neutron scattering, NMR, and ... | Hydrogen pairing; Self-consistent cluster model; Local-density approximation; Energetics | 1989-09 |
263 |
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Bedrov, Dmitro; Smith, Grant D. | Thermal conductivity of molecular fluids from molecular dynamics simulations: application of a new imposed-flux method | We have applied a new nonequilibrium molecular dynamics (NEMD) method [F. Müller-Plathe, J. Chem. Phys. 106, 6082 (1997)] previously applied to monatomic Lennard-Jones fluids in the determination of the thermal conductivity of molecular fluids. The method was modified in order to be applicable to... | Thermal conductivity; Molecular fluids; Heat flux; Imposed-flux NEMD method | 2000 |
264 |
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Liu, Feng | Thermal roughening of a thin film: a new type of roughening transition | The equilibrium thermal roughening of thin Ge layers (one and two monolayers) deposited on Si(001) has been investigated with low-energy electron microscopy. A Ge-coverage-dependent roughening is observed. For two monolayers, the temperature at which imaging contrast is lost due to surface roughness... | Thermal roughening; Roughening transition; Heteroepitaxial growth | 2000-09 |
265 |
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Bedrov, Dmitro; Smith, Grant D. | Thermodynamic, transport and viscoelastic properties of PBX-9501 binder: a molecular dynamics simulation study | Atomistic molecular dynamics simulations were performed on a low molecular weight nitroplasticized Estane® mixture representative of the binder used in PBX-9501. Pressurevolume-temperature (PVT) behavior over a wide range of pressure and temperatures above the order-disorder temperature (ODT) of Es... | PBX-9501 binder; Estane; Viscosity; Shear stress relaxation modulus | 2008-04-04 |
266 |
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Chaudhuri, Reaz A. | Three-dimensional singular stress field at the front of a crack and lattice crack deviation (LCD) in a cubic single crystal plate | A novel eigenfunction expansion technique, based in part on separation of the thickness variable, is developed to derive three-dimensional asymptotic stress fields in the vicinity of the front of a semi-infinite through-crack weakening an infinite plate made of a homogeneous cubic single crystal. C... | | 2010-05-12 |
267 |
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Liu, Feng | Topological and electronic transitions in a Sb(111) nanofilm: the interplay between quantum confinement and surface effect | When the dimension of a solid structure is reduced, there will be two emerging effects, quantum confinement and surface effect, which dominate at nanoscale. Based on first-principles calculations, we demonstrate that due to an intriguing interplay between these two dominating effects, the topologica... | | 2012-01-01 |
268 |
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Liu, Feng | Towards quantitative understanding of formation and stability of Ge hut islands on Si(001) | We analyze Ge hut island formation on Si(001), using first-principles calculations of energies, stresses, and their strain dependence of Ge/Si(105) and Ge/Si(001) surfaces combined with continuum modeling. We give a quantitative assessment on strain stabilization of Ge(105) facets, estimate the cr... | Ge hut islands; Si(001); First-principles calculations; Heteroepitaxial growth | 2005-05 |
269 |
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Chaudhuri, Reaz A. | Transverse shear stress distribution through thickness near an internal part-through elliptical hole in a stretched plate | A semi-analytical post-processing method, termed the equilibrium/compatibility method here, is used for computation of hitherto unavailable through-thickness variation of transverse shear stresses in the vicinity of the circumferential re-entrant corner line of an internal part-through elliptical ... | | 2010-03 |
270 |
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Liu, Feng | Tuning nucleation density of metal island with charge doping of graphene substrate | We have demonstrated that the island nucleation in the initial stage of epitaxial thin film growth can be tuned by substrate surface charge doping. This charge effect was investigated using spin density functional theory calculation in Fe-deposition on graphene substrate as an example. It was found ... | | 2014-01-01 |
271 |
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Liu, Feng | Understanding graphene production by ionic surfactant exfoliation: a molecular dynamics simulation study | We have simulated sodium dodecyl sulfate (SDS) surfactant/waterþbilayer graphene mixture system to investigate two mechanisms of graphene exfoliation: changing the interlayer distance and sliding away the relative distance. By calculating the total energy as a function of the interlayer (sliding-aw... | | 2014-01-01 |
272 |
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Liu, Feng | Unique dynamic appearance of a Ge-Si Ad-dimer on Si(001) | We carry out a comparative study of the energetics and dynamics of Si-Si, Ge-Ge, and Ge-Si ad-dimers on top of a dimer row in the Si(001) surface, using first-principles calculations. The dynamic appearance of a Ge-Si dimer is distinctively different from that of a Si-Si or Ge-Ge dimer, providing a ... | Ge-Si Ad-dimer; Si(001); First-principles calculations; Energetics | 2000-12 |
273 |
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Stringfellow, Gerald B. | Use of Nitrogen to disorder GaInP | Significant changes in microstructure, surface structure, and alloy composition have been observed in GaInP with the addition of nitrogen. These effects occur due to surface changes induced by small concentrations of nitrogen. Transmission electron microscopy and photoluminescence experiments indica... | Nitrogen; Alloys; Transmission | 2004 |
274 |
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Stringfellow, Gerald B.; Shurtleff, James Kevin | Use of surfactant Sb to induce triple period ordering in GaInP | A surfactant is used to induce an ordered structure in an epitaxial layer. The addition of small amounts of triethylantimony during the organometallic vapor phase epitaxy growth of GaInP on 001 GaAs substrates is shown to remove CuPt ordering with a resultant increase in band gap energy. Increasi... | Organometallic; Thermodynamics; Surfactant | 2000-03-13 |
275 |
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Tiwari, Ashutosh | Zn0.9Co0.1O-based diluted magnetic semiconducting thin films | Here we report a systematic study of structural, optical, and magnetic measurements on epitaxial Zn0.9Co0.1O films grown on c-plane sapphire single crystal, at various temperatures (500-650°C), using pulsed-laser deposition. The main emphasis in this work has been on the correlation of microstructu... | ZnO; Cobalt | 2004 |