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Articles 1 - 9 of 9
Full-Text Articles in Physics
Sn Vacancies In Photorefractive Sn2P2S6 Crystals: An Electron Paramagnetic Resonance Study Of An Optically Active Hole Trap, Eric M. Golden, Sergey A. Basun, D. R. Evans, A. A. Grabar, I. M. Stoika, Nancy C. Giles, Larry E. Halliburton
Sn Vacancies In Photorefractive Sn2P2S6 Crystals: An Electron Paramagnetic Resonance Study Of An Optically Active Hole Trap, Eric M. Golden, Sergey A. Basun, D. R. Evans, A. A. Grabar, I. M. Stoika, Nancy C. Giles, Larry E. Halliburton
Faculty Publications
Electron paramagnetic resonance (EPR) is used to identify the singly ionized charge state of the Sn vacancy (V−Sn) in single crystals of Sn2P2S6 (often referred to as SPS). These vacancies, acting as a hole trap, are expected to be important participants in the photorefractive effect observed in undoped SPS crystals. In as-grown crystals, the Sn vacancies are doubly ionized (V2−Sn) with no unpaired spins. They are then converted to a stable EPR-active state when an electron is removed (i.e., a hole is trapped) during an illumination below 100 K …
Sulfur Vacancies In Photorefractive Sn2P2S6 Crystals, Eric M. Golden, Sergey A. Basun, A. A. Grabar, I. M. Stoika, Nancy C. Giles, D. R. Evans, Larry E. Halliburton
Sulfur Vacancies In Photorefractive Sn2P2S6 Crystals, Eric M. Golden, Sergey A. Basun, A. A. Grabar, I. M. Stoika, Nancy C. Giles, D. R. Evans, Larry E. Halliburton
Faculty Publications
A photoinduced electron paramagnetic resonance (EPR) spectrum in single crystals of Sn2P2S6 (SPS) is assigned to an electron trapped at a sulfur vacancy. These vacancies are unintentionally present in undoped SPS crystals and are expected to play an important role in the photorefractive behavior of the material. Nonparamagnetic sulfur vacancies are formed during the initial growth of the crystal. Subsequent illumination below 100 K with 442 nm laser light easily converts these vacancies to EPR-active defects. The resulting S = 1/2 spectrum shows well-resolved and nearly isotropic hyperfine interactions with two P ions and two Sn ions. Partially resolved interactions …
Experimental Tests Of Free-Volume Tracer Diffusion In Water And Other Solvents, Daniel Spiegel, Paulses C. Kollie, Scott J. Van Tilburg
Experimental Tests Of Free-Volume Tracer Diffusion In Water And Other Solvents, Daniel Spiegel, Paulses C. Kollie, Scott J. Van Tilburg
Physics and Astronomy Faculty Research
Using forced Rayleigh scattering, the tracer diffusion of methyl red through water and eight other solvents at different temperatures is investigated and the results are compared to the Cohen-Turnbull theory of free-volume diffusion. In seven solvents the effective non-Arrhenius activation energy measured experimentally agrees with the Cohen-Turnbull energy. In water, however, the diffusion can be described mathematically by the free volume model but there is a disagreement of more than an order of magnitude between these energies. We propose that the unique "zero point" free volume forced onto water by the strong hydrogen bonding requires a different mechanism for tracer …
Structural, Physical, And Electrical Properties Of Boro-Vanadate-Iron Glasses Doped With K_2o Alkali, Harshvadan R. Panchal
Structural, Physical, And Electrical Properties Of Boro-Vanadate-Iron Glasses Doped With K_2o Alkali, Harshvadan R. Panchal
Turkish Journal of Physics
The structural, physical, and electrical properties of semiconducting oxide glasses with composition xK_2O: (95-X) [B_2O_3: 2V_2O_5]: 5Fe_2O_3 (0 \le x \le 30) have been studied. The glasses were prepared by splat-quenching method. Fourier transform infrared spectroscopy (FTIR) studies of these glasses were carried out to study the effect of the modifier and glass former in the glasses. These changes in the molecular structure, bond length, and vibrational group were studied in the spectral range of 400-1350 cm^{-1}. The increase in the intensity and shifting of vibrational bands occurred towards lower wave numbers at 1400-1350 cm^{-1}, 1200 cm^{-1}, and 100-940 cm^{-1}. …
Polarization Of Bi2te3 Thin Film In A Floating-Gate Capacitor Structure, Hui Yuan, Kai Zhang, Haitao Li, Hao Zhu, John E. Bonevich, Helmut Baumgart, Curt A. Richter, Qiliang Li
Polarization Of Bi2te3 Thin Film In A Floating-Gate Capacitor Structure, Hui Yuan, Kai Zhang, Haitao Li, Hao Zhu, John E. Bonevich, Helmut Baumgart, Curt A. Richter, Qiliang Li
Electrical & Computer Engineering Faculty Publications
Metal-Oxide-Semiconductor (MOS) capacitors with Bi2Te3 thin film sandwiched and embedded inside the oxide layer have been fabricated and studied. The capacitors exhibit ferroelectric-like hysteresis which is a result of the robust, reversible polarization of the Bi2Te3 thin film while the gate voltage sweeps. The temperature-dependent capacitance measurement indicates that the activation energy is about 0.33 eV for separating the electron and hole pairs in the bulk of Bi2Te3, and driving them to either the top or bottom surface of the thin film. Because of the fast polarization speed, potentially excellent …
Electrical And Optical Characterization Of Si-Ge-Sn, Merle D. Hamilton
Electrical And Optical Characterization Of Si-Ge-Sn, Merle D. Hamilton
Theses and Dissertations
The electrical characterization of boron-doped p-Si0.08Ge0.90Sn0.02/p-Ge(100) and p-Si0.112Ge0.86Sn0.028/n-Si(100) with various epilayer thicknesses was measured using the Hall effect. The room temperature sheet carrier concentration ranged from 1.21 x 1013 – 1.32 x 1016 cm-2. The room temperature mobilities were measured to be between 166 and 717 cm2/V·s, depending on sample composition. In the low temperature regime, the mobility was mainly affected by ionized impurity scattering. In the high temperature regime, the mobility was mainly affected by …
Activation Energy Of Surface Diffusion And Terrace Width Dynamics During The Growth Of In (4×3) On Si (100) - (2×1) By Femtosecond Pulsed Laser Deposition, M. A. Hafez, H. E. Elsayed-Ali
Activation Energy Of Surface Diffusion And Terrace Width Dynamics During The Growth Of In (4×3) On Si (100) - (2×1) By Femtosecond Pulsed Laser Deposition, M. A. Hafez, H. E. Elsayed-Ali
Electrical & Computer Engineering Faculty Publications
The nucleation and growth of indium on a vicinal Si (100) - (2×1) surface at high temperature by femtosecond pulsed laser deposition was investigated by in situ reflection high energy electron diffraction (RHEED). RHEED intensity relaxation was observed for the first ∼2 ML during the growth of In (4×3) by step flow. From the temperature dependence of the rate of relaxation, an activation energy of 1.4±0.2 eV of surface diffusion was determined. The results indicate that indium small clusters diffused to terrace step edges with a diffusion frequency constant of (1.0±0.1) × 1011 s-1. The RHEED specular …
Amps-1d Modeling Of A-Si:H N^{+}-I-N^{+} Structure: The Validity Of Space Charge Limited Current Analysis, Aynur Eray, G. Nobile
Amps-1d Modeling Of A-Si:H N^{+}-I-N^{+} Structure: The Validity Of Space Charge Limited Current Analysis, Aynur Eray, G. Nobile
Turkish Journal of Physics
In this paper, the AMPS-1D (Analysis of Microelectronic and photonic structure) simulation program is used to understand the origin of the differences observed in Space Charge Limited Current (SCLC) analysis in thin and thick a-Si:H n^{ +} -i- n^{+} structure. For that purpose, the problem of applicability of SCLC measurements to n^{+}-i-n^{+} a-Si:H samples are investigated by using both the thin (0.3 \mu m) and thick (3 \mu m) samples. The simulation results show that activation energy in thick samples is larger than in thinner samples, which are an agreement with the experimental results. It is emphasized that this method …
Thermochemical And Green Luminescence Analysis Of Zinc Oxide Thin Films Grown On Sapphire By Chemical Vapor Deposition, Abdelkader Djelloul, R. A. Rabadanov
Thermochemical And Green Luminescence Analysis Of Zinc Oxide Thin Films Grown On Sapphire By Chemical Vapor Deposition, Abdelkader Djelloul, R. A. Rabadanov
Turkish Journal of Physics
This study has been carried out to detail an integral thermochemical analysis of the principal reaction in the production of zinc oxide (ZnO) thin films, including developing an analytical form of the equilibrium constant. Zinc oxide thin films prepared by chemical vapor deposition have been studied in terms of deposition time and substrate temperature. The growth of the single-crystal films present two regimes depending on the substrate temperature, with increasing constant growth rates at lower, and higher, temperature ranges, respectively. Growth rates above 6 \mu m \cdot min^{-1} can be achieved at T_s = 880 K. The variation of the …