Filters: Department:"Physics" Publisher:"American Institute of Physics (AIP)" School Or College:"College of Science" Collection:"ir_uspace"
| Title | Creator | Description | Subject | Date | ||
|---|---|---|---|---|---|---|
| 1 |  | Atomic scale trap state characterization by dynamic tunneling force microscopy | Williams, Clayton C. | Dynamic tunneling force microscopy (DTFM) is applied to the study of point defects in an inter-layer dielectric film. A recent development enables simultaneous acquisition of DTFM, surface potential, and topographic images while under active height feedback control. The images show no clear correlat... | 2014-01-01 | |
| 2 |  | A contribution to the many-fermion problem | Mattis, Daniel C. | In this work we reexamine the many-fermion problem in arbitrary dimensions. It is shown that in two dimensions or higher, the Hamiltonian of interacting fermions can be separated into individual nonintersecting sectors labeled by the wave-vector q. Within each sector the Hamiltonian maps onto a gene... | 2012-01-01 | |
| 3 |  | Magnetic-field dependent differential capacitance of polymer diodes | Rogachev, Andrey | Using admittance spectroscopy, we found that bipolar organic diodes based on pi-conjugated polymer, 2-methoxy-5-(20-ethylhexyloxy), MEH-PPV, have strong divergent contribution to the device differential capacitance. It is positive at low bias voltages, turns negative at intermediate biases, and beco... | 2012-01-01 | |
| 4 |  | Admittance spectroscopy study of polymer diodes in small magnetic fields | Rogachev, Andrey | We performed a systematic study of bipolar and unipolar organic diodes based on the p-conjugated polymer, 2-methoxy-5-(20-ethylhexyloxy) (MEH-PPV), using electronic and magneto-transport measurements with magnetic field in the range 0-180mT and admittance spectroscopy in the frequency range 1 Hz<f<1... | 2012-01-01 | |
| 5 |  | Probing the electrode-polymer interface in conjugated polymer devices with surface-enhanced Raman scattering | Lupton, John Mark | A crucial consideration in organic devices is the role of the interface between a metal electrode and the active polymer material. Here, we use the conjugated polymer poly[2-methoxy-5-(2-ethylhexyl-oxy)-1,4-phenylene-vinylene] (MEH-PPV) with model gold and silver electrodes to perform surface-enhanc... | 2012-01-01 | |
| 6 |  | Self-switching Q-damping circuit for reducing transmitter ringdown time in high power pulse NMR | Ailion, David Charles | In this paper we describe a circuit for reducing the transmitter ringdown time and thereby improving the recovery time in pulse NMR experiments. The circuit uses only solid state devices and requires no external switching. For transmitter voltages less than 0.5 V peak to peak the effective resista... | Circuits; NMR experiments; Rf pulse | 1970 |
| 7 |  | Quantitative two-dimensional dopant profile measurement and inverse modeling by scanning capacitance microscopy | Williams, Clayton C.; Huang, Yufeng | Quantitative dopant profile measurements are performed on a nanometer scale by scanning capacitance microscopy (SCM). An atomic force microscope is used to position a nanometer scale tip at a semiconductor surface, and local capacitance change is measured as a function of sample bias. A new feedback... | Dopant profile; Capacitance change; Scanning capacitance microscopy; Feedback control | 1995 |
| 8 |  | Direct comparison of cross-sectional scanning capacitance microscope dopant profile and vertical secondary ion-mass spectroscopy profile | Williams, Clayton C.; Huang, Yufeng | The scanning capacitance microscope (SCM) has been shown to be useful for quantitative 2D dopant profiling near the surface of silicon. An atomic force microscope is used to position a nanometer scale tip at a silicon surface, and local capacitance change is measured as a function of sample bias. A ... | Oxide capacitance; Dopant profile; Oxide layer; Scanning capacitance microscopy | 1996-01 |
| 9 |  | Direct imaging of SiO2 thickness variation on Si using modified atomic force microscope | Williams, Clayton C. | Fabrication techniques of metal-oxide-semiconductor ~(MOS) transistors have been improved very rapidly during the last several decades. With this trend, scaling down of MOS transistors is necessary to improve the speed of circuits and the packing density of discrete devices. Both lateral and vertic... | Silicon dioxide; Oxide layer; Phosphorus ions; Oxide capacitance; Dopant profile | 1996-03-01 |
| 10 |  | Directional emission from asymmetric microlaser resonators of ∏-conjugated polymers | Vardeny, Zeev Valentine | A ∏-conjugated polymer film was fabricated into an asymmetric microlaser resonator having a quadrapole deformation with irregular boundaries and a Q factor of 600. At high excitation intensities above the threshold for lasing, we observed multimode laser emission spectra and directional emission a... | Directional emission; Asymmetric microlaser resonators; pi-conjugated polymers; DOO-PPV; poly(dioctyloxy) phenylene vinylene | 2004 |
| 11 |  | 3He spin exchange cells for magnetic resonance imaging | Saam, Brian | We present a protocol for the consistent fabrication of glass cells to provide hyperpolarized (HP) 3He for pulmonary magnetic resonance imaging. The method for producing HP 3He is spin-exchange optical pumping. The valved cells must hold of order 1 atm.L of gas at up to 15 atm pressure. Because char... | 3He; Spin exchange cells; Hyperpolarized 3He; Pulmonary magnetic resonance imaging; Spin-exchange optical pumping; SEOP; Glass cells | 2002 |
| 12 |  | H loss mechanism during anneal of silicon nitride: chemical dissociation | Boehme, Christoph | Remote plasma enhanced chemical vapor deposited silicon nitride (SixNyHz), produced at high ammonia to silane flow rates (ammonia rich) shows a reduction of hydrogen during rapid thermal anneal at temperatures that exceed the deposition temperature. This H release could be either due to a ‘‘slow... | Anneal | 2000 |
| 13 |  | High resolution photothermal laser probe | Williams, Clayton C. | At frequencies near 1 GHz, the acoustic wavelength in argon gas becomes half that of visible light, making possible collinear Bragg scattering of laser light by the sound. This acousto-optic interaction has been used to detect photothermally generated acoustic power at the surface of solids. This ne... | Photothermal laser probe; Silicon wafer | 1984 |
| 14 |  | Highest-energy cosmic rays | Sokolsky, Pierre | What in the cosmos can possibly be accelerating protons to 1020 electron volts and beyond? And how can they preserve such extreme energies while plowing through the cosmic microwave background on their way to us? | Energy spectrum; GZK cutoff; Atmospheric fluorescence | 1998 |
| 15 |  | Photoconductivity and photoinduced absorption in a-Si:F and a-Si:H | Vardeny, Zeev Valentine | The photoconductivity (PC) and photoinduced absorption (PA) of RF glow discharge a-Si:F and a-Si:H samples is reported. The value of the room temperature PC of a-Si:F is lower by some four orders of magnitude relative to that of a-Si:H, but the PA of a-Si:F is found to be significantly higher than t... | Photoinduced absorption; a-Si:F; a-Si:H; RF glow discharge; Spin densities | 1984 |
| 16 |  | Picosecond optical generation and detection of phonon waves in a-As2Te3 | Vardeny, Zeev Valentine | Using the pump and probe technique we have observed oscillations of photoinduced transmission in thin films of a-As2Te3. The oscillations have periods of 70-240 ps, depending on sample thickness. We ascribe these to phonon propagation in the films. Thermal expansion and carrier deformation potenti... | Picosecond optical generation; a-As2Te3; Pump and probe technique | 1984 |
| 17 |  | Picosecond time-resolved photoluminescence spectroscopy of a tetracene film on highly oriented pyrolytic graphite: dynamical relaxation, trap emission and superradiance | Lupton, John Mark | A detailed time resolved investigation of the photoluminescence of a thin tetracene film deposited on highly oriented pyrolytic graphite is presented. In agreement with Lim et al. [Phys. Rev. Lett. 92, 107402 (2004)], we find strong evidence for superradiance: an increase of the relative intensity... | Tetracene film; Pyrolytic graphite Photoluminescence spectroscopy; pi-conjugated polymers; Dynamical relaxation; Trap emission; Superradiance | 2007 |
| 18 |  | Triplet recombination at Pb centers and its implications for capture cross sections | Boehme, Christoph | Pulsed electrically detected magnetic resonance measurements are presented showing that Pb centers at the crystalline silicon (c-Sid) (111) to silicon dioxide sSiO2d interface can cause recombination of strongly coupled spin pairs in singlet and triplet configurations. The implication of these find... | Silicon interfaces | 2005 |
| 19 |  | Two step dopant diffusion study performed in two dimensions by scanning capacitance microscopy and TSUPREM IV | Williams, Clayton C. | We report the results of a two-step two- dimensional (2D) diffusion study by scanning capacitance microscopy (SCM) and 2D SUPREM IV process simulation. A quantitative 2D dopant profile of a gate-like structure is measured with the SCM on a cross-sectioned polished silicon wafer. The gate-like struct... | Scanning capacitance microscopy; SCM; Doping | 1998 |
| 20 |  | Two-dimensional scanning capacitance microscopy measurements of cross-sectioned very large scale integration test structures | Williams, Clayton C. | Scanning probe technology, with its inherent two-dimensionality, offers unique capabilities for the measurement of electrical properties on a nanoscale. We have developed a setup which uses scanning capacitance microscopy (SCM) to obtain electrical information of cross-sectioned samples while simul... | Oxide capacitance; Dopant profile; Scanning capacitance microscopy | 1996-01 |
| 21 |  | Ultrafast intramolecular energy transfer in single conjugated polymer chains probed by polarized single chromophore spectroscopy | Lupton, John Mark | Single molecule spectroscopy of rigid-rod ladder-type conjugated polymers reveals individual chromophore units on a polymer chain, exhibiting fluorescence linewidths of less than 1 nm. Whereas the fluorescence from a single chromophore is fully linearly polarized at low temperatures, a number of exc... | Single molecule spectroscopy; Intramolecular energy transfer; Chromophore spectroscopy; Chromophores; Rigid-rod; Ladder-type | 2004 |
| 22 |  | Unidirectional laser emission from ∏-conjugated polymer microcavities with broken symmetry | Vardeny, Zeev Valentine | We report unidirectional laser emission from ∏-conjugated polymer microcavities with broken symmetry geometries such as spiral and microdisk containing a "line defect," in comparison with plain microdisk cavity having isotropic emission. We found that the laser emission directionality contrast ra... | pi-conjugated polymers; Unidirectional laser emission; Microcavities; DOO-PPV; Poly(dioctyloxy) phenyl vinylene | 2007 |
| 23 |  | Superconducting microphone for photoacoustic spectroscopy | Symko, Orest George | A superconducting microphone has been developed for photoacoustic spectroscopy at low temperatures. The microphone consists of a thin mylar membrane coated with a film of lead whose motion is detected by SQUID magnetometer. For the simple set-up presented here, the limiting pressure sensitivity is ... | Superconducting microphone; Photoacoustic spectroscopy; Low temperatures | 1982 |
| 24 |  | Superconducting properties of polycrystalline Nb nanowires templated by carbon nanotubes | Rogachev, Andrey | Continuous Nb wires, 7-15 nm in diameter, have been fabricated by sputter-coating single fluorinated carbon nanotubes. Transmission electron microscopy revealed that the wires are polycrystalline, having grain sizes of about 5 nm. The critical current of wires thicker than ~12 nm is very high (107 A... | Polycrystalline Nb; Carbon nanotubes; Langer-Ambegaokar-McCumber-Halperin; Phase slips | 2003 |
| 25 |  | Symmetric light emitting divices from poly(p-di ethynylene phenylene) (p-di phenylene vinylene) derivatives | Vardeny, Zeev Valentine | Light emitting devices were fabricated from 2,5-dialkoxy derivatives of poly(p-di ethynylene phenylene-p-di phenylene vinylene) (PDEPDPV) sandwiched between indium tin oxide (ITO) and Al. The current-voltage (Iel-V) curve, electroluminescence (EL) intensity-voltage (IEL-V) curve, and the EL spectra ... | Poly(p-di ethynylene phenylene); PPV; Pi-conjugated polymers | 1995 |