Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 30 for “"Electron affinity"”.
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Negative Surface Ionization and Electron Affinity by Mass Spectrometry
… non-zero gradients of the plots of the ratio the electron to jon current E', the apparent electron affinity was evaluated. The values of E, the actual electron affinity were then calculated from Page's relationship: E'(0) = E + Qr - D Although this study shows that some of the ions assumed to be …
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Photodetachment Studies of Atomic Negative Ions Through Velocity-Map Imaging Spectroscopy
… wavelength of 532 nm. Measurements of the photoelectron angular distributions and asymmetry parameters for Ge- and Sn- were benchmarked against those measured previously [W. W. Williams, D. L. Carpenter, A. M. Covington, and J. S. Thompson, Phys. Rev. A 59, 4368 (1999), V. T. Davis, J. …
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The Effect of Average Grain Size on Polycrystalline Diamond Films
… diamond was studied using ultraviolet photoelectron spectroscopy. Polycrystalline diamond films were deposited onto molybdenum substrates by electrophoresis for grain sizes ranging from 0.3 to 108 microns. The work function and electron affinity were measured using 21.2 eV photons from a …
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Synthesis of Conjugated Polymers
… class of materials because they possess the electronic properties of semi-conductors and processability of polymers. Their electronic and optical properties can be controlled by their chemical structures and conjugation length.To enhance the electron affinity of CPs, a series of …
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Surface transfer doping of diamond for power electronics
… cm⁻². Surface transfer doping using stable high electron affinity transition-metal oxides (TMO) such as WO₃ in conjunction with the novel contact-first process explored in this work shows great promise on advancing process stability while attaining the high current densities desired in the future …
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Efficient Fock Space Configuration Interaction Approaches For Large Strongly Correlated Systems
… spin-flip (SF), ioniza- tion potential (IP), and electron affinity (EA) approaches. This redox spin-flip approach, the restricted active space spin-flip and ionization potential/electron affinity (RAS-SF-IP/EA) method, is applied to several molecules exhibiting double exchange behavior. Model …
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STABILITY AND SPECTROSCOPIC PROPERTIES OF NEGATIVE IONS
… Halogen atoms, due to their ability to attract electrons, readily form negative ions. Considerable interest exists in the design and synthesis of new negative ions called superhaogens whose electron affinities are much higher than those of halogen atoms. This thesis deals with the design of such …
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Synthesis and applications of electron deficient conjugated polymers
… of conjugated polymers for sensory and electronic applications, with a special emphasis placed on electron-deficient materials. Chapter 2. In this chapter is presented the synthesis, characterization, and applications of a series of electron-deficient poly(p-phenylene vinylene)s (PPVs) …
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Fundamental Studies of Reactions between NO3 Radicals and Organic Surfaces
… molecules were identified with X-ray photoelectron spectroscopy (XPS). Consumption of vinyl groups was observed concurrently with formation of organic nitrates in RAIRS. XPS spectra showed little oxidation of sulfur head groups. The observed rate constant was determined based on the …
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Ionisation in Flames with Additives
… negative ions accompanied by a decrease in free electron concentrations. Observations were made of the effects of phosphorus on the ionisation of sodium, potassium, rubidium and caesium. The ionisation of lithium is reduced by extensive hydroxide formation, and was too small for accurate …
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Oxidative addition of N-H and O-H bonds to iridium: developing active catalysts for N-H and O-H additions to unsaturates
… complexes suggests that because of the increased electron affinity of the heteroatoms involved (N or 0), there is high electron density at the heteroatoms in these complexes and therefore the M-N or M-O bond can heterolyze more easily than M-C bonds. This increased tendency of the M-N or M-O bond …
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Space charge resulting from imperfections and effects thereof in ionic crystals
… at a surface is discussed with reference to the electron affinity of ionic crystals. Finally» an experiment is proposed whereby the potential difference across the surface potential field can be measured directly.
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Methodology for determining electronic transference numbers in molten sulfide melts
… efficiency, through, for example, decreasing the electronic transference number of the electrolyte. This thesis compares two methods of determining the electronic transference number in Cu2S - barium sulfide (BaS) electrolytes to determine whether one or both methods are wellsuited for use with …
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Etude par Spectrométrie de Masse de la formation d'Ions Négatifs par Attachement Electronique Dissociatif et par le processus de Paire d'Ions.
… ions by both the mechanism of Dissociative Electron Attachment (DEA) and Ion Pair processes (IPP) by electron impact. Using the appropriate instrumentation (a conventional Nier type mass spectrometer) the best conditions are chosen to ensure ion-molecule collision free ion production (sample …
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DFT study of doped and functionalized fullerene based materials for lithium-ion battery applications
… is quite extensive, the high stability and electron affinity of C60 make C60 based materials attractive for positive electrode applications in lithium ion batteries (LIBs). The rich chemistry of carbon allows fullerene based materials to be doped and functionalized and thereby their …
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Molecular beam studies of excitation and electron transfer reactions
… atoms and some molecules. From the thresholds, electron affinities for SF$\sb6$ and CF$\sb3$Br and the bond dissociation energy for the CH$\sb3$Br bond could be obtained. These values were in good agreement with the literature values, although the electron affinity for CF$\sb3$Br was slightly …
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Liquid crystalline semiconductors for organic electronics
… have been synthesised for use as hole-transport, electron-transport and electroluminescent materials. Many of these materials exhibit nematic phases, which is beneficial for alignment due to the lower viscosity present in the nematic phase compared to the smectic phase. Columnar LCs with low …
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Structural defect engineering of tin (II) sulfide thin films for photovoltaics
… length using high-resolution correlative electron microscopy. The results suggest that intragranular point defects, as opposed to extended structural defects, are likely responsible for the short minority-carrier lifetimes in present-day SnS films. Inhomogeneities in the polycrystalline …
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Computational investigation on polycyclic aromatic hydrocarbons in the molecular and solid phases
… and partial/complete atomic substitution on the electronic (ground-/excited-state) and charge-transport properties of small or- ganic compounds of interest for molecular electronics. In particular, we considered several Polycyclic Aromatic Hydro- carbons (PAHs) with different morphologies …
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Improved mass spectrometry characterization of organic compounds using analyte preconcentration and radio-frequency ionization.
… ionization technique. The possibility of electron emission in RFI, using both direct charged particle current measurements and indirect electron detection, was also studied. We show that RF-generated electrons can be captured by high electron affinity molecules (e.g., hexafluorobenzene) in …
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