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Creator | Title | Description | Subject | Date |
| 276 |
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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 |
| 277 |
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Scarpulla, Michael | Investigation of combinatorial coevaporated thin film Cu 2ZnSnS4 (II): Beneficial cation arrangement in Cu-rich growth | Cu2ZnSn(S,Se)4 (CZTSSe) is an earth-abundant semiconductor with potential for economical photovoltaic power generation at terawatt scales. In this work, we use Raman scattering to investigate phase coexistence in combinatorial CZTS thin films grown at 325 or 470 C. The surface of the samples grown a... | | 2014-01-01 |
| 278 |
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Tiwari, Ashutosh | Manifestation of two-channel nonlocal spin transport in the shapes of Hanle curves | The dynamics of charge-density fluctuations in a system of two tunnel-coupled wires contains two diffusion modes with dispersion iω = Dq2 and iω = Dq2 + 2τt, where D is the diffusion coefficient and τt is the tunneling time between the wires. The dispersion of corresponding spin-density modes de... | | 2014-01-01 |
| 279 |
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Scarpulla, Michael | Effects of sodium on electrical properties in Cu2ZnSnS4 single crystal | We have studied the effect of sodium on the electrical properties of Cu2ZnSnS4 (CZTS) single crystal by using temperature dependence of Hall effect measurement. The sodium substitution on the cation site in CZTS is observed from the increasing of unit-cell size by powder X-ray diffraction. Sodium in... | | 2014-01-01 |
| 280 |
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Liu, Feng | Giant room-temperature spin caloritronics in spin-semiconducting graphene nanoribbons | Spin caloritronics refers to generating spin current by thermal gradient. Here we report a theoretical study demonstrating giant spin caloritronic effects in a new class of materials, called spin semiconductors, which are characterized with a "spin gap," the energy gap between spin-up and -down chan... | | 2014-01-01 |
| 281 |
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Scarpulla, Michael | Investigation of combinatorial coevaporated thin film Cu 2ZnSnS4. I. Temperature effect, crystalline phases, morphology, and photoluminescence | Cu2ZnSnS4 is a promising low-cost, nontoxic, earth-abundant absorber material for thin-film solar cell applications. In this study, combinatorial coevaporation was used to synthesize individual thin-film samples spanning a wide range of compositions at low (325 C) and high (475 C) temperatures. Film... | | 2014-01-01 |
| 282 |
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Liu, Feng | Sd2 graphene: kagome band in a hexagonal lattice | Graphene, made of sp2 hybridized carbon, is characterized with a Dirac band, representative of its underlying 2D hexagonal lattice. The fundamental understanding of graphene has recently spurred a surge in the search for 2D topological quantum phases in solid-state materials. Here, we propose a new ... | | 2014-01-01 |
| 283 |
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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 |
| 284 |
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Liu, Feng | A three-layer-mesh bridging domain for coupled atomistic-continuum simulations at finite temperature: formulation and testing | Although concurrent multiscale methods have been well developed for zero-temperature simulations, improvements are needed to meet challenges pertaining to finite-temperature simulations. Bridging domain method (BDM) is one of the most efficient and widely-used multiscale atomistic-continuum techniqu... | | 2014-01-01 |
| 285 |
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Scarpulla, Michael | Surface stoichiometry of pulsed ultraviolet laser treated polycrystalline CdTe | The effects of nanosecond pulsed ultraviolet laser annealing on the surface stoichiometry of close-space sublimated polycrystalline thin films are investigated using angle-resolved x-ray photoemission spectroscopy (XPS). The raw data suggest the formation of a Cd-rich surface layer, but this is coun... | | 2014-01-01 |
| 286 |
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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 |
| 287 |
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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 |
| 288 |
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Tiwari, Ashutosh | Observation of the inverse spin hall effect in ZnO thin films: an all-electrical approach to spin injection and detection | The inverse spin Hall effect (ISHE) is a newly discovered, quantum mechanical phenomenon where an applied spin current results in the generation of an electrical voltage in the transverse direction. It is anticipated that the ISHE can provide a more simple way of measuring spin currents in spintroni... | | 2014-01-01 |
