Filters: Publication Type:"journal article" School Or College:"College of Engineering" Department:"Materials Science & Engineering" Collection:"ir_uspace" Type:"Text"
| Title | Creator | Description | Subject | Date | ||
|---|---|---|---|---|---|---|
| 1 |  | On the effect of birefringence on light transmission in Polycrystalline Magnesium Fluoride | Shetty, Dinesh K. | Light transmission in polycrystalline magnesium fluoride was studied as a function of the mean grain size at different wavelengths. The mean grain size was varied by annealing hot-pressed billets in argon atmosphere at temperatures ranging from 600 to 800°C for 1 hour. The grain-size and grain-orie... | 2014-01-01 | |
| 2 |  | Pulsed laser processing of electrodeposited CuInSe2 photovoltaic absorber thin films | Scarpulla, Michael | In this report we investigate the effects of pulsed laser annealing (PLA) on both as-electrodeposited (ED) and electrodeposited-furnace annealed (EDA) CuInSe2 (CIS) samples by varying the laser fluence (J/cm2) and number of pulses. Results for as-ED samples indicate that liquid CIS-phase formation d... | 2011-01-01 | |
| 3 |  | Topological and electronic transitions in a Sb(111) nanofilm: the interplay between quantum confinement and surface effect | Liu, Feng | 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 | |
| 4 |  | Molecular dynamics simulation studies of the influence of imidazolium structure on the properties of imidazolium/azide ionic liquids | Smith, Grant D. | Atomistic molecular dynamics simulations were performed on 1-butyl-3-methyl-imidazolium azide [bmim][N3], 1-butyl-2,3-dimethylimidazolium azide [bmmim][N3], and 1-butynyl-3-methylimidazolium azide [bumim][N3] ionic liquids. The many-body polarizable APPLE&P force field was augmented with parameters ... | 2012-01-01 | |
| 5 |  | Detection of ZnS phases in CZTS thin-films by EXAFS | Scarpulla, Michael | Copper zinc tin sulfide (CZTS) is a promising Earthabundant thin-film solar cell material; it has an appropriate band gap of ~1.45 eV and a high absorption coefficient. The most efficient CZTS cells tend to be slightly Zn-rich and Cu-poor. However, growing Zn-rich CZTS films can sometimes result in ... | 2011-01-01 | |
| 6 |  | Electron backscatter diffraction and photoluminescence of sputtered CdTe thin films | Scarpulla, Michael | Electron backscatter diffraction (EBSD) has been used to characterize the grain size, grain boundary structure, and texture of sputtered CdTe at varying deposition pressures before and after CdCl2 treatment in order to correlate performance with film microstructure. It is known that twin boundaries ... | 2011-01-01 | |
| 7 |  | Enhanced light absorption in thin-film silicon solar cells by scattering from Embedded Dielectric Nanoparticles | Scarpulla, Michael | We investigate the light-trapping effects of dielectric nanoparticles embedded within the active semiconductor layer of a thin-film solar cell. The baseline model consists of a 1.0 μm slab of crystalline silicon on an aluminum back contact topped with a 75 nm Si3N4 anti-reflective coating. Using fi... | 2011-01-01 | |
| 8 |  | Self-assembly of three-dimensional metal islands: nonstrained versus strained islands | Liu, Feng | A theoretical model for the Volmer-Weber growth of three-dimensional metal islands is proposed, with a dipolar island edge-edge interaction. The existence of such an island edge effect makes the island shape dependent on island size. Furthermore, it induces a stable island size against coarsening, l... | Self-assembly; Three dimensional islands; Metal islands; Nonstrained islands; Strained islands; Volmer-Weber growth | 2002-11 |
| 9 |  | Self-assembly of two-dimensional islands via strain-mediated coarsening | Liu, Feng | We demonstrate two distinctive effects of strain-induced island-island interaction on island size and spatial distribution during coarsening of 2D islands. When coarsening proceeds via only mass transport between islands, the interaction broadens the island size distribution, leading to a power-law... | Two-dimensional islands; Strain-mediated coarsening | 2001-08 |
| 10 |  | Self-consistent tight-binding method | Liu, Feng | A self-consistent tight-binding formalism is described. The self-consistency is achieved by the introduction of a chemical hardness matrix and a generalization of the Huckel model to make the tight-binding Hamiltonian an implicit functional of the charge density. Studies of the band structures of d... | Tight-binding method; Self-consistency; Huckel model | 1995-10 |
| 11 |  | Self-organization of semiconductor nanocrystals by selective surface faceting | Liu, Feng | The formation and ordering of Si nanocrystals in dewetting and agglomeration of the thin single crystalline Si layer in silicon-on-insulator has been investigated using low-energy electron microscopy. The evolution of the Si dewetting and agglomeration is captured in real time, revealing the detai... | Self-organization; Surface faceting; Silicon nanocrystals; Dewetting | 2005-12 |
| 12 |  | Self-organization of steps in growth of strained films on vicinal substrates | Liu, Feng | Computer simulations show that if stress is present, steps on a vicinal surface can self-organize into a regular array of step bunches. Such self-organization can provide templates for subsequent fabrication of "quantum wire" nanostructures. The size and spacing of the bunches can be controlled inde... | Self-organization; Strained films; Growth; Vicinal substrates; Step bunches | 1998-02 |
| 13 |  | Self-organized nanoscale pattern formation on vicinal Si(111) surfaces via a two-stage faceting transition | Liu, Feng | We demonstrate a self-organized pattern formation on vicinal Si(111) surfaces that are miscut toward the [211] direction. All the patterns, consisting of a periodic array of alternating (7 X 7) reconstructed terraces and step-bunched facets, have the same periodicity and facet structure, independent... | Vicinal Si(111); Nanoscale pattern formation; Two-stage; Faceting transition | 2002-02 |
| 14 |  | Self-organized quantum-wire lattice via step flow growth of a short-period superlattice | Liu, Feng | We develop a theoretical model for step flow growth of multilayer films, taking into account the interlayer step-step interaction induced by misfit strain.We apply the model to simulate the growth of strain-compensated short-period superlattices. Step-bunch ordering improves in successive layers, le... | Quantum-wire lattice; Short-period superlattice; Step flow growth | 2004-06 |
| 15 |  | Self-organized replication of 3D coherent island size and shape in multilayer heteroepitaxial films | Liu, Feng | A model is proposed to elucidate the evolution of the morphology of strained 3D islands in multilayer heteroepitaxial films. The model explains the experimental observation that islands grown in successive layers not only replicate, forming individual island columns, but self-organize to reach a com... | Coherent island size; Island shape; Heteroepitaxial films; Strained 3D islands; Heteroepitaxial films | 1999-03 |
| 16 |  | Quantum size effect on adatom surface diffusion | Liu, Feng | Using scanning tunneling microscopy, we demonstrate that the nucleation density of Fe islands on the surface of nanoscale Pb films oscillates with the film thickness, providing a direct manifestation of the quantum size effect on surface diffusion. The Fe adatom diffusion barriers were derived to be... | Quantum size effect; QSE; Adatoms; Surface diffusion; Fe islands; Nanoscale metallic structures; Epitaxial growth; Pb films | 2006-12 |
| 17 |  | Quantum size effect on the magnetism of finite systems | Liu, Feng | The magnetic moments of the ferromagnetic transition metals Fe, Co, and Ni confined to one-dimensional chains are found to fluctuate with increasing chain length before converging to the infinite limit. This quantum size effect is derived from a simple first-principles theory that we have developed... | Quantum size; Finite systems; Ferromagnetic transition metals; Magnetic moments; Fe; Co; Ni; Molecular-orbital approach | 1990-07 |
| 18 |  | Quantum wells due to ordering in GaInP | Stringfellow, Gerald B.; Inglefield, Colin E.; Taylor, P. Craig | CuPt ordering results in a reduction of the band-gap energy of GaInP. Thus, heterostructures and quantum wells can be produced by simply varying the order parameter, without changing the solid composition. Changes in the order parameter can be induced by changes in growth conditions. The disorder... | Band-gap energy; Growth temperature; Quantum wells | 1998-12-28 |
| 19 |  | Radiative pair transitions in p-type ZnSe:Cu crystals | Stringfellow, Gerald B. | Shallow levels with an ionization energy of 0.012 eV play an important role in the photoelectronic properties of p-type ZnSe:Cu crystals. These levels exhibit the characteristics of the higher-lying member of an imperfection pair involved in luminescence emission, as well as of a trap determining lo... | Ionization energy; Luminescence emission; Crystals | 1968 |
| 20 |  | Diluted II-VI oxide semiconductors with multiple band gaps | Scarpulla, Michael | We report the realization of a new mult-band-gap semiconductor. Zn1-yMnyOxTe1-x alloys have been synthesized using the combination of oxygen ion implantation and pulsed laser melting. Incorporation of small quantities of isovalent oxygen leads to the formation of a narrow, oxygen-derived band of ... | Highly mismatched alloys; Zinc telluride | 2003-12 |
| 21 |  | Magnetization on vicinal ferromagnetic surfaces | Liu, Feng | Using Ising model Monte Carlo simulations, we show a strong dependence of surface magnetization on surface miscut angle. For ferromagnetic surfaces, when surface spin exchange coupling is larger than that of the bulk, the surface magnetic ordering temperature decreases, toward the bulk Curie tempera... | Vicinal ferromagnetic surfaces; Surface magnetization; Surface miscut angle | 1997 |
| 22 |  | Growth and characterization of TaN/TiN superlattice structures | Tiwari, Ashutosh | Epitaxial B1 NaCl-structured TaN(3 nm)/TiN(2 nm) superlattice structures were grown on Si(100) substrates with a TiN buffer layer, using pulsed-laser deposition. A special target assembly was used to manipulate the thickness of each layer. X-ray diffraction, transmission electron microscopy, and ... | Diffusion barriers; Copper diffusion; Tantalum nitride | 2003 |
| 23 |  | Growth of epitaxial NdNiO3 and integration with Si(100) | Tiwari, Ashutosh | We have grown epitaxial NdNiO3 films on Si(100) substrate under ambient oxygen pressure using a pulsed-laser deposition method. The integration of NdNiO3 with Si(100) was accomplished by lattice-matching epitaxy of MgO and SrTiO3 and domain matching epitaxy of TiN on Si(100). During domain matching... | NdNiO3; SrTiO3; Silicon substrate | 2002 |
| 24 |  | Heat flow model for pulsed laser melting and rapid solidification of ion implanted GaAs | Scarpulla, Michael | In order to further understand the pulsed-laser melting (PLM) of Mn and N implanted GaAs, which we have used to synthesize thin films of the ferromagnetic semiconductor Ga1−xMnxAs and the highly mismatched alloy GaNxAs1−x, we have simulated PLM of amorphous (a-) and crystalline (c-) GaAs. We pre... | 2010 | |
| 25 |  | Heterostructures in GaInP grown using a change in Te doping | Stringfellow, Gerald B.; Shurtleff, James Kevin | In organometallic vapor phase epitaxy, changes in growth conditions can be used to modulate the extent of CuPt ordering and, hence, the band gap energy of GaInP. One method is to add Te during growth. An increase in the band gap energy of 0.1 eV due to a decrease in ordering has been obtained by ... | Heterostructures; Alloys | 2000 |