No description available.

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1977. / Bibliography: leaves 229-230. / Microfiche. / xii, 236 leaves ill

Typescript (photocopy) / vi, 65 leaves, [7] leaves of plates : ill. ; 31 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.) Dept. of Physics, University of Adelaide, 1982

Diss. (sammanfattning) Uppsala : Univ., 2003. / Härtill 7 uppsatser.

Diss. (sammanfattning) Uppsala : Univ., 2003. / Härtill 8 uppsatser.

Thesis (Ph.D.) Dept. of Physics, University of Adelaide, 1982. / Typescript (photocopy).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1983. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 301-309).

A novel x-ray anode for electron spectroscopy is investigated for application in the surface analysis field, monochromatic Ag Lalpha (hnu =2984. 3eV), its energy being capable of exciting 1s electrons up to chlorine in the periodic table. Resolution available with this source is satisfactory, with a limitation of approximately 1. 3eV. An increase in sensitivity is achieved for those peaks in the range 1500-3000BE, whilst there is no serious reduction within the conventional XPS energy range. The agreement between experimental sensitivity factors and theoretical cross-section values is good, allowing the transmission function for the VG ESCA3 Mkll spectrometer to be confirmed constant from 0-3000eV. A comprehensive investigation of the LEG51 electron flood gun preceded its successful application for the charge neutralisation of insulating materials. This allowed the application of this source to such materials as chlorides, pertinent to the breakdown in passivity on stainless steels, and silicon compounds, involving thermal oxides on silicon of interest to the microchip industry, zeolites for catalysis in the petrochemical industry and siloxane copolymers for the opthalmic industry. The ability to excite the 1s orbital, together with the 2p and KLL Auger lines, affords calculation of Auger parameters and extra-atomic relaxation energies for the accurate description of the chemical environment of a particular chemical species. A method for internal energy referencing is investigated, involving the vaccum-deposition of Au, Cu and Pt metals. This allows the measurement of photoelectron binding energies to an accuracy of +/-0.1-0.2eV for insulating materials, when referenced to the vacuum level.

In this study, we have investigated the photo-response of gallium antimonide (GaSb) by measuring the spectral, injection level, as well as the temperature dependence of the steady-state photoconductivity of epitaxial films. By combining the various photo-response measurements with-galvanometric measurements, the effective excess carrier lifetimes could be calculated and described in terms of the various experimental variables considered. From a comparison of the measured and theoretical carrier lifetimes, a clear discrepancy was found for the injection dependent results. This inconsistency between the expected and measured behaviours was resolved using a two-layer model to describe the photo-conductive response of the thin film. In this model, the generation/recombination processes are considered for the bulk as well as for a depleted near-surface region. By combining these two contributions when calculating the total excess photocurrent, the various experimental results could be successfully described. The photo-response measurements revealed that the main contribution to the photocurrent came from the near-surface region, where the bandto- band and Auger recombination transitions are reduced. From the simulation of the injection level dependence of the excess carrier lifetime, some of the near-surface characteristics, such as the position of the surface Fermi-level and the surface recombination velocity, could be determined. In the case of p-type GaSb, the room temperature surface Fermi-level was found to be pinned (290±20) meV above the valence band maximum, whereas the n-type material had a pinning position of (150±20) meV above the valence band maximum. These pinning positions were shown to be independent of the doping density and relatively insensitive to the surface treatments considered. The presence of a near-surface depletion region, as well as the position of the surface Fermi-level, was corroborated by Raman spectroscopy. From a comparison of the phonon mode and the phonon-hole plasmon coupled mode, a surface Fermi-level position of (300 ± 30) meV was deduced for p-type GaSb. Finally, the effect various surface treatments have on the photo-response, and related surface properties, were investigated. Removal of the native oxide (HCl:H2O) followed by sulphur passivation (Na2S:9H2O) results in a slight decrease in the surface Fermi-level position. Aging studies however revealed that the surface characteristics reverted back to the untreated values following a few days in air. Coating the GaSb surfaces with a thin ZnS layer was found to have little effect on the surface potential, resulting only in a slight increase in the near-surface donor density. The sensitivity of the measured photocurrent to surface treatments and changes in the ambient with cooling, further validate the importance of considering the surface potential and the related space-charge when describing the photoconductive response of GaSb thin films.

This thesis details the use of x-ray photoelectron spectroscopy to monitor in-situ surface processing of solid surfaces in real-time. The processing methods investigated were annealing, deposition of thin organic films and exposure to oxygen and hydrogen produced by in-situ microwave plasmas. Three solid surfaces were investigated; metals, diamond and zinc oxide. Clean copper and gold were annealed up to 1000 K while monitoring with real-time XPS. A temperature-dependent shift of the Cu 2p3/2 and Au 4f7/2 core-level to lower binding energy was measured, -1.29 ± 0.04 meV/10 K and -2.36 ± 0.01 meV/10 K respectively. The shift was identified as being due to a thermal expansion of the lattice. The removal of argon ion induced damage to the copper surface was monitored in real-time and a critical temperature of 680 ± 20 K for the removal of the damage was measured. The formation of an interface between aluminium and copper phthalocyanine was monitored in real-time. Hydrogen and oxygen terminated (111) natural diamond surfaces were prepared in-situ and surface reconstruction by annealing up to 1200 K was monitored in real-time. Large reversible shifts to core-level binding energies were attributed to a surface photovoltage that was persistent at high temperature on the hydrogen and oxygen terminated surfaces. A model of the surface photovoltage is given where the bulk resistance of the diamond is identified as sustaining the photovoltage at elevated temperature. The zinc oxide (0001) surface was found to have a temperature-dependent core-level binding energy shift that was fully reversible up to 900 K and symmetric with cooling. The shift was attributed to a diffusion of oxygen vacancies from the bulk into the sub-surface. The zinc oxide (0001) surface was found to exhibit different temperature dependence to the (0001) surface that was fully reversible up to 700K but not symmetric with cooling. The shift was attributed to an additional disruption to stabilizing charge transfer between the polar surfaces. The formation of interfaces between the (0001) surface with copper phthalocyanine and C60 were monitored in real-time.