| Plastic Optoelectronics: Injection Lasers Fabricated from Soluble Semiconducting Polymers and Bulk Heterojunction Solar Cells Fabricated from Soluble Semiconducting Polymers |
17 APR 2008 |
15 pages |
| Authors:
Alan J. Heeger; Guillermo Bazan; CALIFORNIA UNIV REGENTS SANTA BARBARA
|
 | We summarize progress on bulk heterojunction (BHJ) "plastic" solar cells: BHJ solar cells are based on phase-separated blends of polymer semiconductors and fullerene derivatives. Because of self-assembly on the nanometer length scale, excitons formed after absorption of solar irradiation diffuse to a heterojunction prior to recombination and are dissociated at the polymer/fullerene interface. Ultrafast charge transfer from semicondueting polymers to fullerenes guarantees that the quantum efficiency for charge transfer (CT) ... |
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| Evolution of the Ion Velocity Distribution in the Near Field of a 200 W Hall Thruster (Preprint) |
JUL 2006 |
12 pages |
| Authors:
Jr. Hargus William A.; Michael R. Nakles; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| This work presents an analysis of near plume velocity distributions of the Busek BHT-200-X3 200 W laboratory Hall thruster derived from laser-induced fluorescence measurements of the 5d[4]7/2-6p[3]5/2 xenon ion excited state transition. The evolution of the axial and radial velocity distributions is presented from the exit plane to approximately 0.7 exit diameters downstream. It is shown that the distributions evolve significantly between the exit channel center and the inner portion ... |
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| High Performance Organic Materials and Devices |
31 MAR 2006 |
30 pages |
| Authors:
Yang Yang; Fredl Wudl; CALIFORNIA UNIV LOS ANGELES DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| During our three-year period of time, significant progresses have been achieved in PLEDs, PV cells and memory devices. First, vertical OFET with astonishing device performance was demonstrated: low operating voltage (< 5 V), high current output (> 10 mA, or 4A/cm2), and high ON/OFF ratio (4 x 10%). These new devices were operated by modulating charge injection, rather than charge transport. This invention opened a new direction in basic scientific ... |
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| Modeling of Multi-Photon Excitations in Charge-Transfer Materials |
SEP 2005 |
3 pages |
| Authors:
Hans A. Agren; ROYAL INST OF TECH STOCKHOLM (SWEDEN)
|
| This report results from a contract tasking Royal Institute of Technology as follows: The aim of the present proposal is to develop and apply a computer code (DALTON) for studies of multiphoton excitations in charge-transfer materials. The basic technology is density functional response theory, originally developed by the Swedish partner, with the intend of this project to implement in such a way that it becomes practical for large scale accurate, ... |
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| A Pulsed-Field Ionization Photoelectron Secondary Ion Coincidence Study of the H2(+)(X, nu(+) = 0 - 15, N(+) = 1) + He Proton Transfer Reaction |
22 APR 2005 |
12 pages |
| Authors:
X. N. Tang; H. Xu; T. Zhang; Y. Hou; C. Chang; C. Y. Ng; Y. Chiu; R. A. Dressler; D. J. Levandier; CALIFORNIA UNIV DAVIS DEPT OF CHEMISTRY
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| The endothermic proton transfer reaction, H2+(v+) + He yields HeH(+) + H(Delta E=0.806 eV), is investigated over a broad range of reactant vibrational levels using high-resolution vacuum ultraviolet to prepare reactant ions either through excitation of autoionization resonances, or using the pulsed-field ionization-photoelectron-secondary ion coincidence (PFI-PESICO) approach. In the former case, the translational energy dependence of the integral reaction cross sections are measured for v+ =0-3 with high signal-to-noise using ... |
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| Reactions of O(+) With C(n)H(2n+2), n=2-4: A Guided-Ion Beam Study |
15 APR 2004 |
10 pages |
| Authors:
D. J. Levandier; Y. Chiu; R. A. Dressler; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
|
| We have measured absolute reaction cross sections for the interaction of 0+ with ethane, propane, and n-butane at collision energies in the range from near thermal to approximately 20 eV, using the guided-ion beam (GIB) technique. We have also measured product recoil velocity distributions using the GIB time- of-flight (TOF) technique for several product ions at a series of collision energies. The total cross sections for each alkane are in ... |
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| Collisional Stabilization and Thermal Dissociation of Highly Vibrationally Excited C9H12(+) Ions from the Reaction O2(+) + C9H12 yields O2 + C9H12(+) |
2004 |
9 pages |
| Authors:
Abel I. Fernandez; A. A. Viggiano; Thomas M. Miller; S. Williams; I. Dotan; J. V. Seeley; J. Troe; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
|
| Highly vibrationally excited n-propylbenzene cations, C9H12(+*), were prepared by the charge transfer reaction O2(+) + C9H12 yields O2 + C9H12(+*) in a turbulent ion flow tube. The subsequent competition between fragmentation of C9H12(+*) into C7H7(+) + C2H5 and stabilization in collisions with N2 was studied at temperatures in the range 423-603 K and at pressures between 15 and 200 Torr. Most of the C7H7(+) is the aromatic benzylium isomer, while ... |
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| Force on an Asymmetric Capacitor |
JUN 2003 |
37 pages |
| Authors:
Thomas B. Bahder; Christian Fazi; ARMY RESEARCH LAB ADELPHI MD
|
| When a high voltage (approx. 30 kV) is applied to a capacitor whose electrodes have different physical dimensions, the capacitor experiences a net force toward the smaller electrode (Biefeld-Brown effect). We have verified this effect by building four capacitors of different shapes. The effect may have applications to vehicle propulsion and dielectric pumps. We review the history of this effect briefly through the history of patents by Thomas Townsend Brown. ... |
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| Spatial Inversion of Gyrotropy Parameter in Conductivity Tensor and Charge Transport Peculiarities |
29 SEP 2000 |
4 pages |
| Authors:
V. R. Sobol; O. N. Mazurenko; M. Zoli; NATIONAL ACADEMY OF SCIENCES MINSK (BELARUS) INST OF SOLID STATE AND SEMICONDUCTOR PHYSICS
|
| Charge transfer is discussed for the case when gyrotropy parameter (Hall coefficient) varies along transport x-direction and inverses its sign. This situation takes place in contacts of the serially joined materials having electron and hole types of conductivity. Spatial inhomogeneity of conductivity and inversion of Hall coefficient sign are analyzed in terms of electric potential and current density distribution. It is shown that under inhomogeneous magnetic field the steady current ... |
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| Charge Transfer Phenomena in Carbon Nanotube Heterodevices |
23 JUN 2000 |
5 pages |
| Authors:
A. A. Odintsov; DELFT UNIV OF TECHNOLOGY (NETHERLANDS)
|
| We describe the transfer of electric charge in junctions between a metal and carbon nanotube as well as between metallic and semiconducting carbon nanotubes. The long range Coulomb interaction drastically modifies the charge transfer phenomena in one-dimensional nanotube systems compared to conventional semiconductor heterostructures. Being brought into a contact with a metal. conducting nanotube accumulates electric charge whose density decays slowly with the distance from the junction. The length of ... |
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| Fractional Charge in Transport Through a 1D Correlated Insulator of Finite Length |
23 JUN 2000 |
2 pages |
| Authors:
V. V. Ponomarenko; STATE UNIV OF NEW YORK AT STONY BROOK DEPT OF PHYSICS AND ASTRONOMY
|
| Transport between two Fermi liquid reservoirs through a one channel wire of length L is examined when the ID electron system has an energy gap 2M: M > T(L) v(c) /L induced by the interaction in its charge mode (v(c)): charge velocity in the wire). In the spinless case transformation of reservoir electrons into solitons of fractional charge entails a crossover from a Fermi liquid regime of integer charge transfer ... |
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| Ultrahigh Density Charge Transfer Device |
07 DEC 1999 |
|
| Authors:
Carmen I. Huber; Tito E. Huber; Nicholas Caviris; DEPARTMENT OF THE NAVY WASHINGTON DC
|
 | Metal heated to a molten state is injected under a high hydrostatic penetration pressure into extremely small and closely spaced channels of an insulating matrix to form an array of electrically conductive pins or wires. The materials for the pins and matrix are selected for compatibility with respect to melting, matrix sintering and surface tension penetration conditions associated with the fabrication of a high density charge transfer device. |
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| Charge Transfer Polymers as Ultrafast Holographic Materials |
1999 |
11 pages |
| Authors:
Alan J. Heeger; CALIFORNIA UNIV SANTA BARBARA INST FORPOLYMERS AND ORGANIC SOLIDS
|
| A summary of the significant scientific accomplishments that resulted from research supported under AFOSR F49620-99-1-0031 is included in this Final Technical Report with emphasis on the following specific areas: (i) Time Resolve Forster Energy Transfer in Polymer Blends (ii) Ultrafast Detection of Charged Photocarriers in Conjugated Polymers (iii) Photophysics of poly(2,3-diphenyl-5- hexyl-phenylene vinylene (iv) Singlet Exciton Binding Energy in Poly(phenylene vinylene) (v) Excitation Spectrum for Ultrafast Photogeneration of Charged Solitons ... |
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| Toward Electrically Pumped Organic Diode Lasers: Electroluminescence of Proton Transfer Polymers |
16 NOV 1998 |
8 pages |
| Authors:
Xuejun Zhang; Richard M. Tarkka; Samson A. Jenekhe; Joseph B. Schlenoff; ROCHESTER UNIV NY DEPT OF CHEMICAL ENGINEERING
|
| Electroluminescence from a series of polymers and copolymers which exhibit photoinduced excited-state intramolecular proton transfer (ESIPT) is reported. Among these polymers containing ESIPT moieties in the main chain or side chain are poly(1,4-(2-hydroxy)phenylene benzobisthiazole-co-decamethylene benzobisthiazole), poly (styrene-co-3-hydroxy-4'-ethenylflavone) and poly(2,5- benzoxazolediyl(2,2,2-trifluoro-1 -(trifluoromethyl) ethylidene)-5,2- benzoxazolediyl-4-hydroxy 1, 3-phenylene). The electroluminescence spectra of these polymers are identical to their photoluminescence spectra, indicating that electroluminescence originates from electrically-generated intramolecular proton transfer (EGIPT). Because electroluminescence from ... |
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| Mechanism of Charge Transfer across Highly Transparent S-N Interfaces in High Temperature Superconductors |
29 AUG 97 |
6 pages |
| Authors:
Sergey K. Tolpygo; Dmitri Averin; STATE UNIV OF NEW YORK AT STONY BROOK DEPT OF PHYSICS AND ASTRONOMY
|
| We have studied the influence of various technological parameters (irradiation dose, spot size, writing time, etc.) on stationary and nonstationary properties of Josephson junctions fabricated by direct electron beam writing and have developed an understanding of the proximity effect and the size and temperature dependence of the Josephson critical current in this type of high-Tc Josephson junctions. Based on the studies of the physical properties of irradiated YBCO films and ... |
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| Studies Concerning Enhancement of Conductivity of Polymer Electrolytes and Stability of Lithium Anodes |
14 FEB 97 |
93 pages |
| Authors:
N. Munichandraiah; INDIAN INST OF SCIENCE BANGALORE
|
| This report results from a contract tasking Indian Institute of Science as follows: The contractor will investigate the passivation process that can result in increased charge transfer and thin film resistance at the lithium electrode polymer electrolyte interface. |
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| Light Induced Cluster-to-Organic-Acceptor Charge Transfer in a Molecular Cadmium Sulfide Assembly |
07 JUN 95 |
18 pages |
| Authors:
Dong I. Yoon; Donald C. Selmarten; Hong Lu; Hui-Jean Liu; Carolyn Mottley; NORTHWESTERN UNIV EVANSTON IL DEPT OF CHEMISTRY
|
| The molecular cluster, (Cd4(S-C6H4NO2)10)?N(CH3)4!2, exhibits an intense near-UV absorption that is absent in the corresponding benzenethiolate cluster. Resonance Raman and electronic Stark effect studies show that the absorption feature originates from a pair of closely spaced cluster-to- nitrobenzene charge-transfer transitions. The lower lying charge-transfer excited state is weakly luminescent. Time resolved luminescence measurements yield a nonradiative decay or back electron transfer rate (nitrobenzene to cluster) of 3.3 x 10(exp 8)/s. ... |
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| Method of Making Ultrahigh Density Charge Transfer Device. |
06 JUN 1995 |
|
| Authors:
Carmen I. Huber; Tito E. Huber; Nicholas Caviris; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| Metal heated to a molten state is injected under a high hydrostatic penetration pressure into extremely small and closely spaced channels of an insulating matrix to form an array of electrically conductive pins or wires. The materials for the pins and matrix are selected for compatibility with respect to melting, matrix sintering and surface tension penetration conditions associated with the fabrication of a high density charge transfer device. |
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| Charge Transport and Water Molecular Motion in Variable Molecular Weight NAFION Membranes. High Pressure Electrical Conductivity and NMR |
26 MAY 95 |
29 pages |
| Authors:
J. J. Fontanella; M. C. Wintersgill; R. S. Chen; Y. Wu; S. G. Greenbaum; HUNTER COLL NEW YORK
|
| Measurements of the electrical conductivity and deuteron NMR spin- lattice relaxation time (T1) in the three different molecular weights of acid form NAFION conditioned at various levels of relative humidity have been carried out. Complex impedance studies were made along the plane of the film at frequencies from 10 to 10(exp 8) Hz at room temperature and pressure up to 0.3 GPa. The NMR measurements were also made at room ... |
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| Charge Transfer Processes on Liquid/Liquid Interfaces: The Status in 1994 |
21 SEP 94 |
24 pages |
| Authors:
P. Vanysek; NORTHERN ILLINOIS UNIV DE KALB DEPT OF CHEMISTRY
|
| Electrochemistry dealing with interfaces between two immiscible and ionically conductive solutions (ITIES) has been documented in literature already a hundred years ago. The thermodynamically grounded interest in electrified interfaces is now just over a century old and it closely follows establishment of physical chemistry as an individual scientific discipline. Its first specialized journal, the Zeitschrift fur physikalische Chemie, founded in 1887 by Wilhelm Ostwald, was in its early years devoted ... |
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| Ion Scattering and Deposition: The Role of Energetic Particles in Thin Film Growth |
31 AUG 94 |
3 pages |
| Authors:
Barbara H. Cooper; CORNELL UNIV ITHACA NY
|
| Energetic ions or neutrals (in the hyperthermal energy range) have been used in a number of thin film growth applications (e.g., sputtering and plasma deposition techniques, direct ion beam and ion-assisted deposition, etc.) . These involve both direct deposition of the film species with an ion beam, and deposition by some other method during simultaneous ion bombardment. Experiments and simulations have shown that energetic ions can lower the substrate temperature ... |
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| Resonant Charge Transfer in Hyperthermal Atomic and Molecular Ion- Surface Collisions |
23 AUG 94 |
35 pages |
| Authors:
Barbara H. Cooper; CORNELL UNIV ITHACA NY LAB OF ATOMIC AND SOLID STATE PHYSICS
|
| We have investigated the interactions of hyperthermal (few to several hundred eV) atomic ions with metal surfaces, in particular the dynamics of electron transfer between the particle and surface. Progress is reported in the following areas: (1) construction of a time-of-flight spectrometer for measuring energy- and angle-resolved distributions of neutral and charged alkali atoms; (2) measurements of the magnitude and velocity-dependence of the neutralization probabilities for Li, Na, and K ... |
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| Semi-Empirical Potential Energy Surfaces of (ArH2O)+ System |
23 JUN 94 |
42 pages |
| Authors:
Michael Baer; I. Last; H. Szichman; ISRAEL ATOMIC ENERGY COMMISSION YAVNE SOREQ RESEARCH ESTABLISHMENT
|
| In order to study the exothermic charge transfer reaction Ar(+) + H2O right arrow Ar + (H2O)(+) the semiempirical calculation of the (ArH2O)(+) potential energy surfaces (PESs) is performed. These PESs are used to calculate the vibrational modes of the molecular species involved, in particular the highly excited vibronic bending modes of the reaction product (H2O)(+). It was found that the bending modes are affected by the stretching bending coupling. ... |
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| Recent Developments in Polymeric Charge Transfer Complexes |
01 MAR 94 |
14 pages |
| Authors:
A. Natansohn; QUEEN'S UNIV KINGSTON (ONTARIO) DEPT OF CHEMISTRY
|
| The recent literature on polymeric charge transfer complexes is reviewed with emphasis on the author's own work. After a definition of the area and a survey of investigations on the spatial arrangement of donor and acceptor sites in the solid state, a variety of applications of these complexes is presented. Electrically conductive polymers are excluded. These applications are: compatibilization of polymer blends, liquid crystalline supramolecular organization, new developments in photoconductivity, ... |
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| Intramolecular Charge Transfer Complexes as Fluorescence Probes for UV and Visible Light Induced Acrylate Polymerization |
FEB 94 |
8 pages |
| Authors:
Jiancheng Song; Afranio Torres-Filho; D. C. Neckers; BOWLING GREEN STATE UNIV OH CENTER FOR PHOTOCHEMICAL SCIENCES
|
| Intramolecular charge transfer complexes (ICTC) of derivatives of 1- diaminonaphthalene-5-sulfonamide (DANSYL AMIDE) such as 1-dimethylamino- naphthalene-5-sulfonyl-n-butylamide (1,5-DASB) and 2-dimethylamino-naphthalene- 5-sulfonyl-n-butylamide (2,5DASB), were used as fluorescence probes for cure monitoring of photocurable polymer systems. This technique is based upon the difference in fluorescence intensity from the parallel and perpendicular conformations of the excited state of the complex, and is based on the dependence of the relative population of each conformation on ... |
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| A Semiclassical Reactive Flux Method for the Calculation of Condensed Phase Activated Rate Constants |
11 JAN 94 |
33 pages |
| Authors:
Diane E. Sagnella; Jianshu Cao; Gregory A. Voth; PENNSYLVANIA UNIV PHILADELPHIA DEPT OF CHEMISTRY
|
| A semiclassical reactive flux algorithm for calculating thermally activated rate constants is presented which is based on a semiclassical transition state theory due to Chapman, Garrett, and Miller J. Chem. Phys. 63 (1975) 2710. This reactive flux technique, when combined with the semiclassical TST, enables one to describe dynamical recrossings of the transition state on the same footing as tunneling effects. Most importantly, the method is readily applied to nonlinear ... |
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| Ultrahigh Density Charge Transfer Device. |
11 MAY 1993 |
|
| Authors:
Carmen I. Huber; Tito E. Huber; Nicholas Caviris; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| Metal heated to a molten state is injected under a high hydrostatic penetration pressure into extremely small and closely spaced channels of an insulating matrix to form an array of electrically conductive pins or wires. The materials for the pins and matrix are selected for compatibility with respect to melting, matrix sintering and surface tension penetration conditions associated with the fabrication of a high density charge transfer device |
|
| Ionization Potentials of Small Carbon Clusters |
05 MAY 93 |
30 pages |
| Authors:
Ragulan Ramanathan; Jeffrey A. Zimmerman; John R. Eyler; FLORIDA UNIV GAINESVILLE DEPT OF CHEMISTRY
|
| Ionization potentials (IP's) of small carbon clusters (C(sub n), n=3- 6) have been bracketed with an uncertainty of a few tenths of an eV by charge- transfer methods in a Fourier transform ion cyclotron resonance mass spectrometer. Values obtained are compared to previously determined experimental and theoretical values. Several interesting reactions other than charge-transfer were observed between the carbon cluster ions and the charge-transfer reference compounds. The products of these ... |
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| Cathode Sheath Charge Transfer Effects |
MAR 93 |
126 pages |
| Authors:
H. H. Michels; R. H. Hobbs; UNITED TECHNOLOGIES RESEARCH CENTER EAST HARTFORD CT
|
| The United Technologies Research Center, under Contract No. F33615- 87-C-2718, has carried out a theoretical research investigation of ion-molecule reactions that take place in the sheath region of low pressure discharges in silane gas mixtures. Of particular interest were the dissociative charge transfer mechanism(s) and energy dependent reaction rates of electrons, H+, H-, H3+ and several noble gas ions (He+, Ne+, Ar+) in collisions with silane (SiH4). Such reactions are ... |
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| Electron Transfer, Proton Transfer and Photoaddition Reactions in Isolated Clusters |
01 FEB 93 |
12 pages |
| Authors:
Elliot R. Bernstein; COLORADO STATE UNIV FORT COLLINS DEPT OF CHEMISTRY
|
| This report contains the abstracts of the published and to be published papers from this work. They include studies of the structure of nonrigid molecules, the formation of clusters and dimers, liquid cluster structure, chemical reaction studies, and studies of cluster dynamics. |
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| Synthetic and Mechanistic Studies on Zinc Tetrabenzporphyrins |
AUG 92 |
|
| Authors:
John W. Cullen; David E. Remy; ARMY NATICK RESEARCH DEVELOPMENT AND ENGINEERING CENTER MA
|
| Tetrabenzporphyrins have been reported to possess very high values for third-order nonlinear optical susceptibility (Chi-3). The preparation of meso substituted zinc tetrabenzporphyrins (TBP's) from isoindole, zinc acetate and aldehydes is described. The scope of the reaction is discussed with regard to several aromatic aldehydes used for the synthesis. Benzaldehydes with electron withdrawing gave little or no product, and sterically hindered aldehydes gave low yields of TBP's that were only partially ... |
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| State-Resolved Reaction Dynamics |
27 JUL 92 |
|
| Authors:
Richard N. Zare; STANFORD UNIV CA DEPT OF CHEMISTRY
|
| This research effort is comprised of two groups of experiments. The first group measures and characterizes the electron ejected in a photoionization event. The second group is concerned with understanding the role of energy in affecting the outcome of ion-molecule reactions. High resolution, angle-resolved photoelectron spectroscopy was carried out following resonance enhanced multiphoton ionization (REMPI) of nitric oxide. These measurements have led to a complete description of this photoionization event. ... |
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| Multi-Ion Ambipolar Diffusion |
JUL 92 |
|
| Authors:
Thomas E. Gist; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
|
| The continuity and momentum equations for electrons and multiple ion species are solved analytically and numerically using a new model for ambipolar diffusion. The general form of the model is valid for any quasi-neutral plasma for which the diffusion approximation is appropriate, including positive or negative ions, arbitrary geometries, and time dependence. The model provides criteria for determining when single ion diffusion theory is appropriate for describing multi-ion discharges, when ... |
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| Near-Surface Type Conversion of p-type Single-Crystal InP by Plasma Exposure, |
JUL 1992 |
|
| Authors:
X. Li; T. A. Gessert; T. J. Coutts; SOLAR ENERGY RESEARCH INST GOLDEN CO
|
| During the past several years considerable work has gone into describing why a buried homojunction forms during direct current (dc) magnetron sputter deposition of indium tin oxide (ITO) on single-crystal, p-type InP. Several mechanisms have been suggested to account for the resulting device behavior. Bachmann suggested that type conversion may be due to substitutional doping by Sn, while Tsai et al. believed that sputter damage was a possibility. In our ... |
|
| Particle Emission and Charging Effects Induced by Fracture |
30 JUN 92 |
16 pages |
| Authors:
J. T. Dickinson; WASHINGTON STATE UNIV PULLMAN
|
| We summarize three research areas that have focused on surface dynamics associated with fracture and UV laser bombardment of materials. These studies have been based on our capabilities to a) detect and characterize particle release from surfaces on fast time scales, and b) to obtain high resolution topographical information utilizing scanning tunneling and atomic force microscopy. Three principle areas of study have been fracto-emission, scanning tunneling microscopy studies of fracture ... |
|
| The Peierls Ground State, Solitons and Polarons in Ring-Containing Polymers |
05 JUN 92 |
11 pages |
| Authors:
A. J. Epstein; PENNSYLVANIA UNIV PHILADELPHIA DEPT OF CHEMISTRY
|
| The report of doping of polyacetylene to form a highly conducting polymer opened the question concerning the nature of the electronic states of the polymer backbone that are formed upon charge transfer between the polymer and dopant backbone. Extensive study of polyacetylene has demonstrated that this system is a degenerate Peierls semiconductor with a bandgap introduced through bond alternation. Pernigraniline is a semiconductor analogous to trans- polyacetylene. However, it differs ... |
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| Ionization Potentials and Electron Affinities of Semiconductor Clusters Determined via Charge Transfer Reactions |
28 MAY 92 |
17 pages |
| Authors:
S. H. Bach; J. E. Bruce; R. Ramanathan; C. H. Watson; J. A. Zimmerman; FLORIDA UNIV GAINESVILLE DEPT OF CHEMISTRY
|
| This chapter summarizes ONR-supported work in Prof. Eyler's laboratories involving small clusters of As, C, and P. Charge transfer bracketing experiments involving cluster ions and neutral molecules of known electron affinities (E.A.) and ionization potential (I.P.) lead to precise estimates of E.A.'s and I.P.'s for the clusters studied. Ionization Potentials, Electron Affinities, Semiconductor Clusters, Cluster Ion Reactions |
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| Ion/Molecule Reactions of Metal and Semiconductor Clusters: Ionization Potentials and Electron Affinities |
28 MAY 92 |
|
| Authors:
S. B. Bach; J. E. Bruce; M. A. Cheeseman; R. Ramanathan; C. H. Watson; FLORIDA UNIV GAINESVILLE DEPT OF CHEMISTRY
|
| This chapter summarizes ONR-supported work in Prof. Eyler's laboratories involving small clusters of As, C, and P, and the coinage metals Ag, Au, and Cu. Charge transfer bracketing experiments involving cluster ions and neutral molecules of known electron affinities (E.A.) and ionization potential (I.P.) lead to precise estimates of E.A.'s and I.P.'s for the clusters studied. Ionization Potentials, Electron Affinities, Semiconductor Clusters, Cluster Ion Reactions, Coinage Metal Clusters. |
|
| Vibrational Modes and the Dynamic Solvent Effect in Electron and Proton Transfer |
18 MAY 92 |
8 pages |
| Authors:
Paul F. Barbara; Gilbert C. Walker; Terrance P. Smith; MINNESOTA UNIV MINNEAPOLIS DEPT OF CHEMISTRY
|
| This article primarily reviews recent work on ultrafast experiments on excited state intramolecular electron and proton transfer, with an emphasis on experiments on chemical systems that have been analyzed theoretically. In particular, those systems that have been quantitatively characterized by static spectroscopy, which provides detailed information about the reaction potential energy surface and about other parameters that are necessary to make a direct comparison to theoretical predictions, are described. ... |
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| Charge Transfer Processes in Multiple Site Chemical Systems |
31 MAR 92 |
|
| Authors:
Thomas J. Meyer; NORTH CAROLINA UNIV AT CHAPEL HILL DEPT OF CHEMISTRY
|
| Based on support from AROD, we have investigated redox and photochemical events in polypyrrole based polymeric films, and charge transfer processes in systems containing more than one redox site covalently attached to either soluble polymer or to solid supports. Binding and electrode position of metal particles into vinyl-bipyridyl based films were also achieved. Optical and thermal electron transfer in mixed-valence dimeric systems were studied in some detail. Chromophore/quenchers in pyrrole ... |
|
| Cathode Sheath Charge Transfer Effects |
JUL 91 |
139 pages |
| Authors:
H. H. Michels; Robert H. Hobbs; UNITED TECHNOLOGIES RESEARCH CENTER EAST HARTFORD CT
|
| The United Technologies Research Center, under WL Contract No. F33615-87-C-2718, has carried out a theoretical research investigation of ion- molecule reactions that take place in the sheath region of low pressure discharges in silane gas mixtures. Of particular interest were the dissociative charge transfer mechanism(s) and energy dependent reaction rates of electrons, H+, H-, H3+ and several noble gas ions (He+, Ne+, Ar+) in collisions with silane (SiH4). Such reactions ... |
|
| The Charge-Exchange Neutral Problem and the Code NEUTRAL |
26 JUN 91 |
|
| Authors:
John M. Les; Robert E. Terry; NAVAL RESEARCH LAB WASHINGTON DC
|
| The code named NEUTRAL was developed to simulate the problem of charge- exchange neutrals, which has been proposed to explain the anamolous gap closure in a Reflex Switch. NEUTRAL is one dimensional in position and velocity space and includes a static electric field. Monte Carlo techniques are used to model the charge-exchange process. Analytic expressions are derived using the one dimensional Boltzmann equation, assuming a constant charge-exchange cross section, and ... |
|
| Experimental Assessment of Dynamic Structural Parameters for Homogeneous and Interfacial Charge-Transfer Reactions: Case Studies Based on Time-Dependent Raman Scattering Methods |
19 APR 91 |
45 pages |
| Authors:
Steven K. Doorn; Robert L. Blackbourn; Christopher S. Johnson; Joseph T. Hupp; NORTHWESTERN UNIV EVANSTON IL DEPT OF CHEMISTRY
|
| The application of time-dependent scattering methodologies to dynamic structural problems involving charge transfer reactions is described. We show experimentally that a time-dependent analysis of resonance-enhanced Raman scattering can lead to a complete mode-by-mode description of the vibrational structural changes accompanying charge transfer and, therefore, a complete description of the vibrational activation barrier to charge transfer. (In other words, all force constants, all mode displacements, al bond length displacements, and all ... |
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| Cooperative Absorption-Induced Charge Transfer in a Solid |
DEC 90 |
|
| Authors:
Isidore Last; Thomas F. George; STATE UNIV OF NEW YORK AT BUFFALO AMHERST
|
| Cooperative electronic excitation involving electron transfer among guest molecules in a solid is considered. The mutual interaction between two guest molecules with large dipole moments in excited states can lead to cooperative processes (two-electron transfer) which are forbidden in the absence of such interaction. The cooperative transition moments are calculated for coupled pairs of XeC1 molecules within an Ar matrix at sum and difference frequencies. Keywords: Charge transfer, Solid, Cooperative ... |
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| Non-Destructive Characterization of Polymer/Metal Interphases Using Surface-Enhanced Raman Scattering |
01 JUN 90 |
|
| Authors:
F. J. Boerio; P. P. Hong; W. H. Tsai; J. T. Young; CINCINNATI UNIV OH DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| Surface enhanced Raman scattering (SERS) is an analytical technique in which the Raman scattering cross sections of molecules adsorbed onto the roughened surfaces of certain metals are enhanced by as much as six orders of magnitude compared to their value for normal Raman scattering. The mechanisms are associated with the large electric fields that can be induced at the surfaces of metal particles having small radii of curvature and with ... |
|
| Ion/Molecule Reactions of Arsenic and Phosphorus Cluster Ions: Ionization Potentials and Novel Reaction Pathways |
18 MAY 90 |
|
| Authors:
Jeffrey A. Zimmerman; Stephen B. Bach; Clifford H. Watson; John R. Eyler; FLORIDA UNIV GAINESVILLE DEPT OF CHEMISTRY
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| Ionization potentials (IP's) for arsenic and phosphorus clusters (Asn, n = 1-5; Pn, n = 1-4) have been determined by gas phase charge transfer reactions. Arsenic and phosphorus cluster ions were generated by pulsed CO2 laser desorption from GaAs and InP substrates, mass selected, thermalized, and allowed to react with compounds of known ionization potential in a Fourier transform ion cyclotron resonance mass spectrometer. The IP's for As3 and As5, ... |
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| A Viologen/Ruthenium Oxide-Based Microelectrochemical Diode with pH- Dependent Current-Voltage Characteristics |
16 MAY 90 |
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| Authors:
Martin O. Schloh; Mark S. Wrighton; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF CHEMISTRY
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| A procedure for selectively derivatizing two adjacent (approx. 1.4 microns apart) microelectrodes with RuOx and the redox polymer derived from hydrolysis of N,N'-bis(p-(trimethoxysilyl)benzyl)-4,4' bipyridinium dichloride, (BPQ2+), n' to yield a physical RuOx/(BPQ2+)n junction is reported. Such a junction functions as a pH-dependent diode by virtue of the redox properties of the materials employed. A diode-like current voltage curve obtains, because charge transport across the RuOx/(BPQ2+)n junction is effectively unidirectional: the ... |
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| Towards a Quantum Pump of Electric Charges and Currents |
MAY 90 |
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| Authors:
Q. Niu; CALIFORNIA UNIV SANTA BARBARA DEPT OF PHYSICS
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| We give a critical examination of the possibility of realizing a quantum pump of electric charges and currents. The physics is based on the theory of quantum adiabatic particle transport initially due to Thouless. We present theoretical guide lines on the experimental conditions for observing this phenomenon. We argue that potentially very accurate quantization of charge transport or electron current can be achieved, once these conditions are approximately satisfied. An ... |
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| Towards a Quantum Pump of Electric Charges and Currents |
DEC 89 |
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| Authors:
Q. Niu; CALIFORNIA UNIV SANTA BARBARA DEPT OF PHYSICS
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| Here we give a critical examination of the possibility of realizing a quantum pump of electric charges and currents. The physics is based on the theory of quantum adiabatic particle transport initially due to Thouless. We present theoretical guide lines on the experimental conditions for observing this phenomenon. We argue that potentially very accurate quantization of charge transport or electron current can be achieved, once these conditions are approximately satisfied. ... |
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| Electronic Energies for Neon Dimer Dication Radiative Charge Transfer |
DEC 89 |
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| Authors:
Roger A. Deemer; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
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| This research was conducted to find the shape of the potential energy surfaces for the Neon dimer dication, designated Ne2(+2), to include all symmetries which dissociate to two ground state Ne(+) ions or a ground state Ne atom and Ne(+2) ion. The motivation is to investigate whether there is a minimum in the upper level, the Ne(+2) and Ne level, located in such a way that populations of bound dimer ... |
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Reports by Keyword(s)
*CHARGE TRANSFER
